PART II

THE TRUE BUTTERFLIES

SUPERFAMILY _Papilionoidea_

The great suborder of butterflies is commonly separated into two

principal groups called superfamilies. One of these includes all of

the higher butterflies and is named _Papilionoidea_. The other

includes the lower Skipper butterflies and is named the

_Hesperioidea_. The former are characterized by small bodies and

relatively large wings, straight clubbed antennae, and the fact that

the caterpillars do not make cocoons when preparing for the chrysalis

state.

The most authoritative classifications of butterfly families are based

upon the peculiarities of wing venation and are admirably discussed in

such books as Holland's "Butterfly Book" and Comstock's "How to Know

the Butterflies." Without attempting to go into the technical details

of structure it will suffice here to give the list of families which

compose the superfamily _Papilionoidea_:

The Parnassians. _Parnassiidae._

The Swallowtails. _Papilionidae._

The Whites, Orange-tips, and Yellows. _Pieridae._

The Nymphs. _Nymphalidae._

The Satyrs or Meadow-browns. _Agapetidae._

The Heliconians. _Heliconidae._

The Milkweed Butterflies. _Lymnadidae._

The Long-beaks. _Libytheidae._

The Metal-marks. _Riodinidae._

The Gossamer-wings. _Lycaenidae._

It must not be thought that such a list necessarily indicates the

degrees of development of the respective families, for this is not

true. It is simply a linear arrangement adopted for convenience by

leading authorities, notably Dr. Harrison G. Dyar in his standard

"Catalog of American Lepidoptera."

THE PARNASSIAN BUTTERFLIES

FAMILY _Parnassiidae_

It is perhaps a bit unfortunate that the group of butterflies, which

is commonly chosen to head the list of families, is one that is rarely

seen by most collectors. The Parnassians are butterflies of the far

north or of high elevations in the mountains. The four species

credited to North America have been collected in Alaska and the higher

elevations of the Rocky Mountains, so there is very little probability

of any of them being found in the Eastern states.

While, structurally, these butterflies have a close affinity with the

Swallowtails, one would never suspect it from their general

appearance. Their bodies are large and all of the wings well rounded,

so that there is more of the suggestion of a large moth than of the

Swallowtail. The coloring is also more moth-like than with most

butterflies, the wings being very light colored and nearly

transparent, with markings of gray and brown, arranged in dots and

splashes.

All our species belong to the genus Parnassius. The caterpillars show

their affinity with those of the Swallowtails by having the curious

scent organs or osmateria just back of the head. They feed upon such

alpine plants as stonecrop and saxifrage and are well adapted by their

structure and habits to the bleak surroundings of the mountain tops.

As a typical example of the environment in which these butterflies

live, we may take the alpine valleys of such mountain regions as

Pike's Peak. Prof. M. J. Elrod has described a visit where, at an

altitude of 11,500 feet in the month of August, _Parnassius smintheus_

was flying by thousands, and the earlier stages were so abundant that

a water ditch had the surface covered as far as one could see with the

dead or dying caterpillars. In such situations, where ice forms at

night, and snow frequently falls by day, these butterflies develop

apparently in greater numbers than almost any of our other species are

known to do in warmer regions.

THE SWALLOWTAILS

FAMILY _Papilionidae_

This is probably the most distinctive family of all our familiar

butterflies. Its members are characterized by being on the whole the

largest butterflies in our region and by having the hind wings

prolonged into curious tail-like projections, suggestive of those of a

swallow. In general, the basal color of the wings is blackish though

this is commonly marked in various striking ways with yellow, green,

or blue, while the margins of the wings are commonly adorned with red

or orange spots. These butterflies are also characterized by certain

peculiarities in the branching of the wing veins which will be found

pictured in more technical works.

The caterpillars of these butterflies have the characteristic form

pictured on the plate of the Swallowtails opposite page _80_. When

full grown they are large, fairly smooth-bodied worms, showing at most

on the surface sparse fine hairs or fleshy threadlike projections.

Their most characteristic feature is found in the scent organs called

_osmateria_ situated in the back just behind the head. These are

thrust out, generally, when the caterpillar is disturbed and appear as

orange Y- or V-shaped organs from which an offensive odor is commonly

given off. They are supposed to serve the purpose of preventing injury

by enemies, possibly birds, monkeys, and other vertebrates.

Structurally, they are like long tubular pockets that can be turned

inside out. When the pocket is in place it is getting a pocketful of

odors. When it is inverted it lets these odors free. On this account

Professor Comstock has aptly called these caterpillars "the polecats

of the insect world."

When ready to pupate, these Papilio caterpillars spin a web of silk

upon some more or less flattened surface and a loop of silk near by.

They entangle their hind legs in the former and keep their heads

through the latter so the loop supports the body a little behind the

head. Then they change to chrysalids which are held in place by these

sets of silken threads.

The chrysalids are rather large and angular and generally take on

colors approximating their surroundings. They vary so much in

different species that one familiar with them can recognize the

chrysalis and know the kind of butterfly it will produce.

=The Black Swallowtail=

_Papilio polyxenes_

While the Black Swallowtail is not so large as some other members of

the group, it is probably the best known to most people. It is found

throughout many months of the year in practically all parts of North

America south of Canada, and has the habit of flying freely about

fields and gardens in search of flowers from which to suck its nectar

food, and of plants on which to deposit its eggs. The female

butterflies have a remarkable ability in selecting only members of the

great family Umbelliferae for this purpose. In consequence the

caterpillars are generally to be found feeding upon carrots, parsnips,

parsley, and various wild species belonging to this order. (_See

plates, pages 48 and 64-65._)

The eggs of the Black Swallowtail are laid one in a place upon the

leaves of the food plant. Each egg is a small, yellowish, smooth, and

ovoid object. It may often be found by watching the butterflies as

they fly low in search of umbelliferous plants, and seeing one stop

for a minute or so while she lays the egg.

About ten days after the egg is laid it hatches into a small black

caterpillar marked in a characteristic fashion with a blotch of white

in the middle of the body which is suggestive of a saddle. The

caterpillar immediately begins to feed upon the green substance of the

leaf, continuing thus about a week before the first moult. At this

time it does not change much in appearance, still being a spiny

creature blackish in color and marked by the curious white saddle. A

little later it moults again, retaining its original coloring. At each

moult, of course, it gets larger and feeds more freely upon the celery

or other plant on which it may happen to be.

When the caterpillar becomes about half grown it takes on a very

different appearance from that of its early life. The skin is smooth

rather than spiny, and the general colors are green, black, and

yellow. The ground color of the skin is green, which is marked with

black cross-bands along the middle of each body ring. On these bands

there are many large dots of orange yellow, the whole coloring giving

the insect a very striking appearance, especially when it is placed by

itself against a plain background. When they finally become full grown

in this larva state, these caterpillars are almost two inches long.

The larvae of the Black Swallowtail have certain characteristics in

which they differ from many other caterpillars. After each moult they

do not devour their cast skins, which happens in the case of many of

their relatives. When feeding, as well as when resting, they remain

exposed upon the leaf and seem never to attempt to conceal themselves,

as is the habit with a large proportion of caterpillars. It is

probable that this instinct for remaining exposed to view bears some

relation to the curious means of protection possessed by this as well

as other Swallowtail caterpillars. When disturbed one of these larvae

will push out from just back of the head the strange-looking,

orange-yellow Y-shaped organ which gives off a very disagreeable odor.

These osmateria organs are generally believed to be defensive against

the attack of birds and various other enemies, although they seem not

to be effective against insect parasites.

The full-grown caterpillars are likely to leave their food plants when

ready to change to the chrysalis state. They wander in various

directions until suitable shelter is found. A piece of board, a fence

post, or possibly the bark of a tree will answer for this purpose.

Here the caterpillar spins a mat of silk in which to entangle its hind

legs and a short distance away near the front end of the body it spins

a loop of silk attaching the ends to the support. These serve to hold

the chrysalis in place during this helpless period. After the loop is

made the caterpillar keeps its head through it so that the loop holds

the insect in position a short distance back of the head. It is now

ready to moult its last caterpillar skin and become a chrysalis.

One who has watched hundreds of these caterpillars go through this

change, Miss Mary C. Dickerson, describes the process in these words:

"In this final moult the chrysalis has to work very hard. The bulk of

the body is again slipped forward in the loosened caterpillar skin, so

that this becomes tensely stretched over the anterior end, and very

much wrinkled at the posterior end. The skin splits back of the head

and is forced back by its own taut condition and by the efforts of the

chrysalis, until only the extreme posterior end of the chrysalis is

within it. Then the chrysalis withdraws this posterior end with its

many very tiny hooks, from the skin on the dorsal side, and, reaching

around, securely fastens the hooks into the button of silk. Then the

old skin is removed both from its fastening to the chrysalis and from

its attachment in the button of silk."

A short time after the caterpillar's skin has thus been cast off the

chrysalis takes on a brownish color which as is so often the case is

likely to vary somewhat according to the tint of the surrounding

surfaces. This is doubtless a protective device and helps the insect

to escape attack by birds during the long period of exposure. For this

butterfly passes through the winter only in the chrysalis condition,

and the larva which went into the chrysalis in September does not come

out as a butterfly until the following May or June. There are,

however, two broods of the butterflies in the North and at least three

in the South. As the adults live for about two months and there is

considerable variation in the periods of their development it happens

that one can find these Black Swallowtail butterflies upon the wing

almost any time in warm weather, either North or South.

=The Giant Swallowtail=

_Papilio thoas_

The largest of our North American butterflies is a magnificent insect

with a wing expanse of some four inches and with a rich coloring of

black and yellow more or less suffused with greenish or bluish

iridescence that gives it a striking beauty as it flies leisurely

about from flower to flower or stops to lay an egg upon some bush or

tree. The tails are long and expanded toward the tip, their prevailing

color being black with a broad splash of yellow near the end. In a

general way we may say that the upper wing surface is black marked

with two bands of orange-yellow, while the under surface is yellow

marked with two bands of black. (_See plate, page 64._)

The Giant Swallowtail is a tropical species which is abundant

throughout the Southern states and during recent years seems to have

been gradually extending its northern range. It is now commonly found

as far north as forty-two degrees latitude, from Nebraska eastward. In

New England it is occasionally taken in Connecticut, Massachusetts,

and even in Maine, but its appearance in this region is exceptional.

In the orange-growing regions of the Southern states the caterpillars

of this butterfly feed freely upon the leaves of citrus fruits and

they are often called "orange puppies" or "orange dogs." Probably

their curious appearance and their habit of resting for long periods

upon leaf or twig gave rise to this name. In the region indicated the

life-history of the insect may be summarized thus:

The mother butterfly deposits the eggs singly upon the young growth of

orange or other citrus fruit trees, generally near the tips of leaves

or branches. About a week later each egg hatches into a caterpillar

that feeds upon the young leaves, resting upon the lower surface when

not eating. After a few days of this feeding the caterpillar becomes

too large for the skin with which it was born and it moults, coming

forth with a new skin which soon hardens so that it can begin feeding

again. A week or so later it moults for the second time, and continues

these processes of feeding and moulting until full grown, which is

perhaps a month from the time of hatching from the egg. At first the

caterpillars eat only the succulent young leaves and branches, but as

they grow larger they feed more freely upon the older foliage. They

are very voracious and when abundant may often do much damage

especially to young trees. When ready to change to the chrysalis each

caterpillar attaches itself by silken threads to the bark of the

trunk or branch of the tree. Here it changes to a chrysalis which

takes on a color so similar to that of the bark that the insect is

surprisingly difficult to discover. A fortnight or so later it changes

again into a fully developed butterfly that sallies forth in search of

the nectar of flowers. (_See plate, page 240._)

These "orange dogs," like the caterpillars of other Swallowtail

butterflies, have curious yellow scent organs which, when the

caterpillar is disturbed, protrude from the upper surface just behind

the head. These give forth a very disagreeable odor which is believed

to serve the purpose of repelling birds and possibly other enemies. It

has been noticed that these caterpillars are not molested by birds

although they are attacked by various insect enemies. Each mother

butterfly is known to be able to deposit four or five hundred eggs and

it has been suggested that the injuries of the caterpillars may be

checked by shooting the butterfly upon the wing with cartridges loaded

with small bird shot. In the South there are several broods in a

season.

The life-history of this species in more northern regions differs in

the choice of the food plant and the number of broods. It feeds upon

various members of the rue family, including common rue and prickly

ash, as well as upon certain poplars and probably other trees. It is

two brooded and apparently winters as a chrysalis. The butterflies of

the first brood come from the chrysalis about the last of May and are

found on the wing during June. Those of the second brood come from the

chrysalis about the last of July and are found on the wing during

August and September. The length of time required from the laying of

the egg to the emergence of the butterfly varies greatly with the

locality and the temperature. It commonly extends over a period of

four or five weeks.

[Illustration: _From a drawing by Mary E. Walker_ _See page 62_

GIANT SWALLOWTAILS

Visiting blossoming branches of the orange tree. (Reduced)]

[Illustration: _See page 59_

BLACK SWALLOWTAIL VISITING THISTLE, SHOWING THE TONGUE

PARTIALLY UNCOILED]

[Illustration: _Photographed from life_ _See page 83_

IMPORTED CABBAGE BUTTERFLY

(A good deal magnified)]

[Illustration: _See page 65_

THE BLUE SWALLOWTAIL

Upper surface above; lower surface below]

=The Blue Swallowtail=

_Laertias philenor_

The Blue Swallowtail is said to have closer affinity with the splendid

butterflies of the tropics than most of our other Papilios. The sheen

of metallic color upon its wings is certainly suggestive of the broad

expanse of similar colorings in the gorgeous butterflies from South

America. This species is easily recognized by the general blackness of

the front wings and the basal parts of the hind ones as seen from

above, about two thirds of the area of the latter being overlaid with

blue-green scales that give the metallic lustre characteristic of the

species. Near the outer border of the basal half of the front wings

there is a row of about five rather indistinct whitish spots, this row

being continued more distinctly on the hind wings. On the under

surface the white spots of the front wings are more pronounced than on

the upper, while each hind wing is brilliantly marked with about seven

large orange spots, part of them fringed on one or both sides with a

distinct margin of white. The extreme side borders of all four wings

are distinctly marked with white crescents and the fringes on the

tails as well as more or less of the darker fringes of the hind wings

are of a beautiful purple color. In the males each hind wing has along

the inner border a slender, pocket-like depression which is said to be

the seat of the scent organs. (_See plate, page 65._)

This splendid butterfly is a southern species. It is found from the

Carolinas to California, being at times extremely abundant in certain

localities over this great region. It seldom occurs as far north as

New England and in a general way east of the Rocky Mountains its

northern limit approximates that of forty-three degrees of latitude.

It varies considerably in size and differs greatly in abundance in

different localities and different seasons.

[Illustration: Caterpillar of the Blue Swallowtail.

(After Riley)]

Probably the commonest food plant of the caterpillars is the

Dutchman's Pipe or Aristolochia, which is frequently planted as an

ornamental vine for porch adornment. It also feeds upon wild ginger or

Asarum and probably upon other plants. A dozen or more eggs are laid

upon a leaf by the mother butterfly, usually in a cluster or grouped

near together. They hatch a week or so later into small brownish

caterpillars which remain together for awhile in little groups that

feed side by side upon the leaf, beginning at the margin and working

toward the centre. As they become larger they feed more freely and

gradually disperse so that each forages for himself. As they approach

maturity their appetites become voracious and their presence is often

shown by the defoliated condition of the branches. They have back of

the head the osmateria or scent organs which are commonly found in

the other caterpillars of this genus, but the odor emitted by them is

likely to be less pronounced than usual.

[Illustration: TWO OF THE SWALLOWTAILS

(Three fourths natural size)

The Palamedes (_see page 76_)

The Giant (_see page 62_)]

[Illustration: _See page 67_

THE GREEN-CLOUDED SWALLOWTAIL

Upper surface above; lower surface below]

When full grown the caterpillars find such shelter as they may and

each spins a bit of silken web and a silken loop which hold it while

it changes to the chrysalis. This chrysalis is very likely to take on

the colors of the immediate surroundings and thus be rather difficult

to see. If the egg was laid by one of the spring or early summer

butterflies, the chrysalis will soon change to a butterfly which will

appear toward midsummer and which may lay eggs for another brood of

caterpillars. These caterpillars mature to chrysalids the same season

and some of them are believed to change into butterflies in autumn,

these butterflies hibernating through the winter; while others are

believed to remain unchanged through the winter and disclose the

butterfly the following spring. This is an exceptional condition for

the Swallowtails and it is worth while to make careful observations

along its northern limits to learn more definitely the facts as to the

winter condition.

=The Green-clouded Swallowtail=

_Papilio troilus_

This beautiful butterfly is essentially a southern species and is

found over a wide range of territory from the Mississippi River to the

Atlantic Ocean. It occurs as far north as New Hampshire and Vermont

and has even been reported from Alberta, Canada. It is easily

recognized by the blue-green clouding of the upper surface of the

wings, the general color being velvety black with distinctive rows of

yellow spots along the margins of the front wing. These spots are

present also on the hind wing where they are almost changed to blue

because overlaid with a general cloudiness of this color. On the under

surface of the hind wings there are two rows of orange-brown spots,

the inner row being nearly crescent-shaped and the outer row oblong.

In the living insect the tail projections on the hind wings are

usually twisted into a vertical plane at right angles to the plane of

the wings.

The caterpillars of this species feed upon the leaves of sassafras and

spice bush. The distribution of the butterfly appears to be closely

related to the distribution of these plants.

As is the case with so many of our Swallowtail butterflies, the

Green-clouded Swallowtail passes through the winter in the chrysalis

stage. Late in spring the butterflies emerge and soon afterward lay

their eggs singly upon the leaves of sassafras or spice bush. The eggs

soon hatch into lead-colored caterpillars, largely covered with spiny

warts. Each caterpillar cleverly makes a protecting nest by eating out

a narrow strip in the leaf which frees a flap along the margin that is

turned back upon the leaf, making a case in which the larva lives. It

spins a silken carpet on one side of the case and rests upon this

carpet when at home. During its feeding periods it goes outside and

eats the tissues of the other parts of the same leaf. It continues to

occupy this first nest for a week or more by which time the rest of

the leaf is likely to be pretty well consumed.

Having passed the first moult and thus become larger and having

practically eaten itself out of its first house and home the

caterpillar now crawls to a larger leaf where it proceeds to make a

more enduring structure. In this case it does not need to bite a

channel along one side of the midrib as it did before, but instead it

begins to spin silken threads transversely across the upper surface in

such a way as to fold over the border of the leaf and make a tubular

chamber in which it has plenty of room to move about. It uses this as

its home for some time thereafter, wandering out at evening to feed

upon neighboring leaves as its hunger necessitates. In this way it

continues to feed and grow for a week or two. Then it finds it

necessary to construct still another home, which it does by bringing

together the opposite sides of a leaf, taking care to have a door-like

opening at the base of the blade next the leaf stalk. This third home

serves it to the end of its larval existence. It goes in and out as

necessary, remaining concealed when it casts its skin and until the

body tissues harden afterward. Apparently it devours the cast skin and

thrusts the hard covering of the head out of the nest. Consequently

these little homes are clean and sanitary and serve admirably their

protecting purpose.

The full-grown caterpillars have the curious appearance of those of

the other Swallowtails. The third ring behind the head is greatly

swollen, making, with the rings directly in front of it, a

characteristic picture suggesting a grotesque face with large eye-like

spots at the top. The general color is green, darker above than below,

and there are six rows of blue dots along the body. (_See plate,

page 80._)

When ready to change to the chrysalis, the caterpillars desert their

leafy homes and on a twig or board or stone each spins a bit of silken

webbing and a silken loop. They now change to chrysalids which are

likely to resemble the color of the background and which are somewhat

smoother than many of the Swallowtail chrysalids. About two weeks

later the butterflies emerge.

_The Eclosion of the Butterfly_

The transformation of a chrysalis into a butterfly is always one of

extraordinary interest. Comparatively few definite descriptions of

this process have been given by careful observers. One of the best of

these is that written by Mr. Scudder in connection with the emergence

of this butterfly, and it is so accurate and complete that it seems

worth while to quote it at length:

"The butterfly generally emerges from the chrysalis early in the day,"

writes Mr. Scudder, "and the first signs of the immediate change are

strong forward and backward movements of the chrysalis at intervals of

a few seconds; perhaps the third or fourth attempt will be successful,

when a click may be heard at the distance of several feet; but all the

subsequent movements are absolutely noiseless, though rapid; at

intervals of three or four seconds, spasmodic movements similar to the

first carry on the process; first the split continues along the

thorax; then it runs down either side between the legs and wings,

ultimately to the tips of the antennae. As this progresses, the

actions become more strenuous and more frequently repeated; with eager

efforts the butterfly pushes forward its half-detached head; now an

antenna springs from its case, at once assuming its natural attitude;

the other soon follows, and then the wings are partially drawn from

their sheaths, and while in this position seem to be used as levers or

arms to aid in withdrawing the rest of the body; next the legs appear,

seize the upper part of the chrysalis skin, and speedily withdraw the

whole body. It is now a curious-looking object, the wings wrinkled

and bloated, and, although the whole process of escape lasts little

more than half a minute, already twice the size of the sheaths they

lately occupied. The insect crawls upward until it finds a secure

resting place, and there remains until ready for flight; each half of

the tongue, drawn independently from its receptacle, is rolled in a

separate spiral, and now while the wings are gradually expanding the

insect applies all its energies to uniting their two parts,

incessantly rolls and unrolls them, and beginning simultaneously at

the base, gradually fits them together by their interlocking joints;

in about fifteen minutes all but the tips are perfectly united; these

require nearly fifteen minutes more, and are not fairly interlocked

until the wings are fully expanded, nearly a full half hour after the

escape from the chrysalis; the wings, however, are still tender, and

generally require two hours to stiffen. When at last the insect

ventures upon flight, it is not with an uncertain flutter, but boldly

and steadily, as if long accustomed to the action."

The butterflies of this second brood of the season are likely to begin

to appear early in August, continuing to become more abundant

throughout that month. These lay eggs upon the same food plant and the

caterpillars grow to maturity in the same way as those of the first

brood. They become full grown during September or October, and then

change to chrysalids which remain dormant until the following spring.

The species thus has two broods each year and passes the winter only

in the chrysalis state.

These beautiful butterflies are likely to be found in the sort of

situations where the food plants of the larvae are growing. Open

groves, the borders of woods, and the margins of streams or marshes

are the places where one is most likely to find spice bush and

sassafras. These are the places to look for these butterflies which

one may often see in graceful flight near the ground, pausing now and

then to seek a sassafras leaf or to sip the nectar from a flower.

=The Tiger Swallowtail=

_Papilio glaucus_

One of the many things that make a study of the life-histories of

butterflies of great interest is the variations in the development of

many of the species. One who follows the simplest life-story of a

butterfly and sees the egg change to larva and the larva change in

size and form and color with each successive moult and then change

again into the seemingly inert chrysalis, from which there finally

comes the winged butterfly--unlike the egg, unlike the larva, unlike

the chrysalis--a creature of perfect beauty, wonderfully adapted to

living freely in the air and sipping ambrosial nectar from the

flowers--one who follows these changes with awakened vision can

scarcely fail to have a sense of wonder as to the laws that govern

such intricate phenomena. But the marvel is still more pronounced in

the case of those butterflies which have two or more forms arising

from the same lot of eggs in a way which science has as yet not

adequately explained.

The splendid Tiger Swallowtail is an example of this dimorphism which

is of especial interest because of the fact that the extra form is

confined to one sex and to only a part of the geographical area over

which the butterfly is found. The species occurs over a very large

part of the North American continent, being found from ocean to ocean

and from Canada to Florida. In the region north of approximately the

fortieth degree of latitude there is but one form of the insect--the

familiar yellow-and-black striped butterfly which every one has seen

visiting the lilac blossoms in May or June. South of this, however,

part of the females take on an entirely different appearance, being

almost wholly black with the hind wings touched with lines of blue and

bordered with crescents of yellow and orange. The curious thing about

it is that a certain mother butterfly may lay a dozen eggs part of

which will develop into the usual yellow form and the rest into the

black form, both lots being of the same sex. This black form is so

entirely distinct in appearance that the two were originally described

as separate species, and they were long considered such, until

breeding experiments determined the precise condition. (_See plate,

page 17._)

This species is of interest also for another reason. The caterpillars

during their later life are remarkable examples of that curious

resemblance to the head of a serpent which is thought to have a real

protective value in frightening away attacking birds and possibly

other enemies. The rings of the body just back of the head are much

swollen and on the top of the swollen part there are two large

circular marks which bear a striking resemblance to eyes. When the

insect is at rest it withdraws its head and holds up the front of the

body in such a way as certainly to suggest at the first glance that

one is looking at the head of a small snake, an impression which is

likely to be enhanced when the caterpillar pushes out the curious

yellow scent organs from the ring near the top of the head, these

organs taking on the forked appearance of a snake's tongue.

Obviously it is exceedingly difficult to get definite observations

under natural conditions to determine whether these seeming

resemblances are really of value to the caterpillar in frightening

away birds or other enemies. About the only direct evidence which I

have come across upon this point is found in this paragraph by Dr. J.

L. Hancock:

"When I recall the first sight of this larva, the impression gained of

it was a most curious one. The forward mask-like face was remarkably

startling. This mask, bearing eye-like spots and the light transverse

ridge, gave it an aspect which might easily be mistaken for real eyes

and a mouth. This contrivance is only a false face in no way connected

with the real eyes and mouth. One might imagine the shock that a bird,

or other predaceous enemy, would experience when looking upon this

grinning mask. This is in reality the effect produced, for I have seen

small birds so alarmed that they lost their appetite and curiosity for

these larvae after a brief glance at them. It is certain that these

singular markings have the effect of terrifying their bird

enemies."[B]

[B] "Nature Sketches in Temperate America," p. 146.

The yearly cycle of the Tiger Swallowtail is much like that of the

related species. It passes the winter as a chrysalis, the butterflies

coming forth just about the time that the lilacs bloom. They remain

upon the wing for a few weeks and deposit their eggs upon a great

variety of trees and shrubs, for the food plants of the larvae are

unusually varied and include tulip trees, birches, wild cherries,

apples, poplars, ash, and several other common trees or shrubs. These

eggs soon hatch into caterpillars that feed upon the leaves and make

for themselves resting places by spinning a web of silk transversely

across the surface of the leaf. They remain upon these silken webs

when not feeding and in later life are likely to cause the leaf on

which the web is made to curl into a partial tube. When fully

developed they change to chrysalids which give forth the summer brood

of butterflies in July and August. These in turn lay eggs for the

caterpillars which change to chrysalids in autumn and remain in that

condition until the following spring.

=The Short-tailed Papilio=

_Papilio brevicauda_

Were one enough of a magician to make one butterfly over into another

it would be comparatively easy to take a Black Swallowtail and

transform it into this species. One would only need to trim off the

long tails so that they project very slightly from the angles of the

hind wings and to change the yellow spots to orange. He would thus

accomplish what Nature through the long ages seems to have

accomplished in a limited northern area in Newfoundland and around the

Gulf of St. Lawrence, for the Short-tailed Papilio is confined chiefly

to this region, where it lives a life very similar to that of the

Black Swallowtail. The caterpillar feeds upon the leaves of various

members of the parsley family and is said to have learned to warm

itself during the middle of the day by resting upon stones and gravel

which have absorbed the sun's heat rays. Presumably there is but one

brood a year and the insect hibernates as a chrysalis.

=The Palamedes Swallowtail=

_Papilio palamedes_

If the magician who had succeeded in converting a Black Swallowtail

into the Short-tailed Papilio wished to try his hand on making a

Palamedes Swallowtail he could not do better than to use again the

same black butterfly. He would only need to make it about one half

larger, retaining practically all its color markings and the outline

of its wings and tail. For this species bears a remarkable resemblance

to the Black Swallowtail, seeming to be a giant variety induced by the

warmth of the southern climate where it lives, and possibly by the

more generous supply of the magnolia and sassafras leaves upon which

the caterpillars feed.

This species is distinctly a southern form occurring as far west as

the Mississippi River throughout the more Southern states. As one

would expect in the long seasons and warm climate of this region there

are several broods each year and the caterpillars often hibernate as

well as the chrysalids. The adult butterflies are lovers of the sun

and are said to roost at night upon the tops of live oak and palmetto

trees.

=The Zebra Swallowtail=

_Iphiclides ajax_

Most of our Swallowtail butterflies are so distinctive in form and

colors that they are easily distinguished from one another, but the

Zebra species is so different from all the rest that when it is once

seen it is likely always to be remembered. The striking combination of

green and black stripes with very long tails, set off by beautiful

crescents of blue and of red, at once distinguishes this fine

butterfly in any of its varying forms.

Three distinct forms of this species occur, namely:

_Marcellus_, the early spring form, small in size with short tails,

that show white only on the tips;

_Telamonides_, the late spring form, somewhat larger, with tails a

little longer and showing more white on the outer half;

_Ajax_, the summer form, decidedly larger with tails very long.

It would be a comparatively simple matter to understand these forms if

they were simply seasonal variations, with three broods, each form

succeeding the other as the season advances. But this is far from

being the case. We have instead the most complicated and confusing

series of conditions imaginable--conditions for which no one has yet

given satisfactory explanations.

To make a fairly clear statement of what happens, suppose we assume

that we start with twenty over-wintering chrysalids. In April ten of

these disclose their butterflies which are Marcellus, the early spring

form. In May the other ten disclose their butterflies which are

Telamonides, the late spring form. We thus have these two forms,

appearing successively in spring from the same set of over-wintering

chrysalids.

After flying about for a short time the Marcellus or early spring

Swallowtails lay eggs upon the leaves of papaw trees or bushes. These

eggs soon hatch into caterpillars that feed upon the leaves and grow

rather rapidly. A little more than a month later they mature into

butterflies which are Ajax, the summer form.

In a similar way the Telamonides or late spring butterflies lay eggs

soon after they appear, also upon papaw leaves, and these eggs in

about a month mature into Ajax, the summer form.

So we have Ajax, the summer form, developing directly from both the

early spring or Marcellus and the late spring or Telamonides

butterflies.

These Ajax butterflies in their turn lay eggs for caterpillar young.

These soon mature into a brood of butterflies which are of this same

Ajax form. There may be successive broods through the summer,

practically all of them being this same Ajax summer form.

The last brood of caterpillars, however, change to chrysalids which do

not disclose the butterflies until the following spring. And then the

first that come out are the Marcellus form and the last the

Telamonides form. So we may have these two forms maturing from the

same brood of autumn caterpillars.

This seems a sufficiently complicated life-history to suit the most

persistent solver of puzzle problems, but there is an additional

factor which adds much to the possible confusion of the broods. In

each brood of caterpillars from the earliest to the latest there are a

certain number of chrysalids which remain dormant through the

remainder of the season and the following winter, maturing into

butterflies the next spring. Consequently at the end of every winter

there are a miscellaneous lot of chrysalids which represent every

brood of caterpillars that lived the previous season, and all of these

develop into either Marcellus or Telamonides butterflies.

Such a condition of affairs certainly represents what an old New

Englander would be likely to call a "mixed-up mess," and it is

difficult for science to find rhyme or reason to explain it. It speaks

eloquently for the perseverance of W. H. Edwards that he was able with

infinite patience through years of study and experiment to untangle

this intricate web of butterfly existence.

While the preferred food plant of this species is papaw, the

caterpillars are also known to feed upon the spice bush and upland

huckleberry. When full grown these caterpillars are about two inches

long and of a general pea-green color, banded transversely with yellow

and black, and having an especially conspicuous band of this sort on

the third ring behind the head. The scent organs are protruded when

the larva is disturbed and emit an offensive odor. The chrysalids are

green or brown according to the surroundings.

The Zebra Swallowtail is a southern butterfly found as far west as

Texas and the Rocky Mountains and having its northern limits in a zone

ranging approximately from Massachusetts to Nebraska. It is especially

abundant in the Southern states east of the Mississippi River.

Mr. S. F. Denton found this species abundant in southern Ohio where

the females laid their eggs upon the small papaw bushes. They selected

the leaves of these bushes for sleeping quarters, "clinging to the

under side of the leaves where early in the morning they might be

taken with the fingers."

_Other Swallowtails_

Several other Swallowtail butterflies are found within the limits of

the United States, especially in the Far West and along the southern

boundaries. Some of these occasionally migrate east or north so that

they are collected in the Central states. Thus _Papilio daunus_, _P.

oregonia_, and _P. zolicoan_ are all found in the "List of Nebraska

Butterflies," published by Mr. H. G. Barber, and the same species have

been taken in other states in or near the Mississippi Valley. These

and various others are described and pictured in Dr. Holland's

excellent "Butterfly Book."

_Synopsis of the Swallowtails_

_Tiger Swallowtail_: _Yellow form_ (_Papilio glaucus turnus_). Expanse

3 1/2 to 5 inches. Upper surface of wings bright yellow with each

black margin marked with a row of yellow spots. Both sexes throughout

its range. _Black form_ (_Papilio glaucus glaucus_). Black all over

with blue markings on outer half of hind wings and row of straw-yellow

crescents on borders of same. Females only, and only south of about

latitude 40 degrees.

_Giant Swallowtail_ (_Papilio thoas_ or _Papilio cresphontes_).

Expanse 4 to 5 1/2 inches. Upper surface black with two bands of

yellow starting at the inner margin of the hind wings and coming

together as a row of yellow spots at the outer angles of each front

wing. A yellow spot on each black tail. Under surface yellow.

_Zebra Swallowtail_. Expanse 3 to 3 1/2 inches. Easily known by the

stripes of green upon black and the long, slender tails. The different

forms vary in size and in the length of the tails. Scientific names

are: Early Spring Form, _Iphiclides ajax marcellus_; Late Spring Form,

_I. ajax telamonides_; Summer Form, _I. ajax ajax_.

[Illustration: _From a photograph from life by A. H. Verrill_

_See pages 7, 67_

CATERPILLARS OF THE GREEN-CLOUDED SWALLOWTAIL

In various stages of growth]

[Illustration: _Photographed from life_ _See page 83_

IMPORTED CABBAGE BUTTERFLY]

[Illustration: _Photographed from life_ _See page 215_

BLUE-EYED GRAYLING VISITING JOE PYE WEED

(Magnified)]

_Green-clouded Swallowtail_ (_Papilio troilus_). Expanse 3 1/2 to 4

inches. Black with about seven yellowish spots on outer margin of each

front wing and eight marginal spots on each hind wing, those at the

ends of row orange, the rest yellowish or bluish. Outer half of hind

wings clouded with greenish blue. Under surface black with two

distinct rows of yellowish spots on front wings and two rows of orange

spots on hind wings.

_Blue Swallowtail_ (_Laertias philenor_, often called _Papilio

philenor_). Expanse about 4 inches. Black or brownish black with most

of hind wings showing a bluish green iridescence. A row of marginal

spots on each hind wing, more or less distinct on the front wings.

Outer fringe with broad white markings interrupted by black ones.

Under surface of each hind wing with seven large orange spots, some

with partial borders of white.

_Black Swallowtail_ (_Papilio polyxenes_ or _Papilio asterias_).

Expanse about 3 inches. Black with two conspicuous rows of yellow

spots on outer half of wings, more distinct in males. On hind wings

rows of blue spots or splashes between the yellow ones. Orange-red

circle with black centre at inner angle of each hind wing. Under

surface with markings more distinct and more orange-yellow.

_Short-tailed Swallowtail_ (_Papilio brevicauda_). Much like the Black

Swallowtail but generally smaller, with very short tails, and with the

yellow markings more or less changed to orange. Confined to the

limited region of Newfoundland and the lands bordering the Gulf of the

St. Lawrence.

_Palamedes Swallowtail_ (_Papilio palamedes_). Expanse 4 to 4 1/2

inches. Much like the Black Swallowtail but considerably larger. A

curved yellow line on the head back of each eye. Found only in the

South.

THE WHITES, ORANGE-TIPS, AND YELLOWS

FAMILY _Pieridae_

The most familiar and abundant American butterflies are classified

together under the family name _Pieridae_, or the Pierids. Three

groups or tribes of them are popularly known as the Whites, the

Orange-tips, and the Yellows. Our two commonest butterflies, the White

or Imported Cabbage Butterfly and the Sulphur Yellow Butterfly, are

typical representatives of this family. Most of the rest, like these,

are of moderate size with rounded wings which are more or less marked

with black. There are six well-developed legs and the caterpillars of

practically all the species are cylindrical greenish worms which under

a lens are seen to be covered with short hairs. When the caterpillars

are ready to change to chrysalids they spin a web of silk upon the

supporting surface and just back of it, a loop of silk that serves to

hold the chrysalis in place and keep it from swaying back and forth.

The chrysalids are characterized by having a pointed projection on the

front of the head, the rest of the body being more or less angular.

Notwithstanding their close general resemblance to their food plants,

the caterpillars of this family suffer from attack by various enemies.

Birds find many of them, not only eating them themselves but also

using them freely for feeding the nestlings. Parasitic insects also

take a heavy toll from these caterpillars. This attack of enemies is

doubtless a chief reason why many of the common species are not much

more destructive.

THE TRIBE OF THE WHITES

Three white butterflies of approximately the same size are found

widely distributed over the United States. The most abundant species

is the White or Imported Cabbage butterfly. The next in abundance is

probably the Checkered White, and the rarest in most localities is the

Gray-veined White which is a northern form.

=The White or Imported Cabbage Butterfly=

_Pieris rapae_

There is probably no butterfly which one can generally find so easily

in its early stages as the White or Imported Cabbage butterfly which

is found practically wherever cabbages are grown and is generally so

abundant that caterpillars and chrysalids are readily discovered. In

the Northern states the insect passes through the winter within the

chrysalis, coming forth rather early in spring as the familiar white

butterfly with black dots upon the wings and blackish front angles of

the fore wings. (_See plates, pages 64-65 and 81._)

The butterflies that thus appear in spring flit freely about over

fields, meadows, and gardens, sipping the nectar of various early

flowers through their long, coiled tongues and stopping occasionally

to alight upon the leaf of a cabbage or other plant of the mustard

family to deposit the small, pale yellow eggs which remain attached by

a sort of glue. The adult butterflies continue their leisurely life

for a fortnight or more, thus extending the laying of the eggs over a

considerable period.

About a week after being deposited the egg hatches into a tiny green

caterpillar that begins feeding upon the tender surface of the cabbage

leaf. It is commonly called the cabbage worm and it is doubtless the

most generally destructive insect affecting this crop. It continues to

feed for several days before the first moult, after which it becomes

decidedly larger and begins to eat again more voraciously than before.

It undergoes several successive moults during the next two or three

weeks before it becomes full grown as a caterpillar. Unlike most

butterfly larvae it has changed very little in its general appearance

during its growth. It is always of a pale green color, strikingly like

the glaucous green of the cabbage leaf, a fact which doubtless helps

to conceal it from the eager eyes of birds and other animals.

When the caterpillar is thus full fed it is likely to leave its food

plant and find shelter elsewhere. Sometimes it will stop on the lower

surface of the outer leaves, but more commonly it will find a piece of

board, an overhanging stone, a fence-post, or the side of a building,

where it will prepare for the change to the chrysalis. It will do this

by spinning a silken thread upon the surface in which to entangle its

hind legs and a loop of silk near by with which to hold its body. When

these preparations are completed the insect will cast its last

caterpillar skin, emerging as a grayish or brownish chrysalis, the

color usually varying with the color of the surrounding surface.

A week or more later the chrysalis skin bursts open and the white

butterfly emerges to expand and dry its wings before it flies away for

its leisurely life. There are two or more broods each season, the

number varying with the latitude. There is a decided variation in the

length of time required for the completion of the cycle from egg to

butterfly. In hot weather the insect may mature in about three weeks

while in cooler weather it may require as much as five weeks.

_Its Introduction and Dispersal_

While it is well known that a large proportion of our most destructive

insects have been imported from Europe, it is only in comparatively

few cases that man has been able to make careful records of the times

and places where the insects were introduced and to follow the spread

of the pest from these original centres. The Imported Cabbage

butterfly is one of the few species of which this is true. This insect

has been known for centuries in Europe, where it feeds freely upon the

leaves of cabbages and turnips. So far as known it was first

introduced into North America about 1860, when it appeared in Quebec.

Eight years later it was again introduced into the region of New York

City. From these two points the insect spread gradually in various

directions until in 1871 it covered the whole of New England and

various parts of New York and New Jersey. From then on it spread even

more rapidly and was evidently accidentally introduced into various

parts of the country which became new centres of distribution. Of

course it would be very easy for this to happen through the shipment

of cabbages from one part of the country to another. Within thirty

years of the time of its first introduction it had become a serious

pest over practically all the United States and Canada.

The introduction and spread of such a pest is of interest in itself,

but in this case there is to be noted the additional fact that the

presence of this foreigner has practically led to the extinction of

two native species of butterflies, both closely related to each other

and to the invader and both feeding upon the same plants. An almost

pure white butterfly--the Gray-veined White--was formerly exceedingly

abundant in many of the Northern states, while farther south there was

another species, the Checkered White, which was also abundant. Both of

these have now so completely disappeared that in some localities they

are almost never seen, while their imported relative has become

perhaps the most abundant of all American butterflies.

=The Gray-veined White=

_Pieris napi_

One would naturally suppose that when a butterfly was reduced to the

greatest possible simplicity in its coloring there would be little

chance for the development of geographical or seasonal varieties. But

he would only have to study a large collection of specimens of this

species, taken at different seasons and in different regions, to find

his supposition at fault. Here is a butterfly which is essentially a

slender black-bodied creature with four white wings scarcely touched

with color, and yet we are told that there are eleven varieties in the

United States so distinct that they have received scientific names,

not to mention various others which have been found in Europe. This

is indeed a remarkable showing and it is a striking illustration of

the infinite variations which Nature can produce with the most limited

materials.

To me the seasonal variations of a butterfly are always of greater

interest than those which are geographical. We know that in the case

of a great many animals, from insects to mammals, the different

conditions of climate and physical environment found in different

regions produce variations of many sorts. So it does not seem

especially strange that in Alaska there should be a different form of

a certain butterfly than is found in Virginia. But that in the same

locality there should be two or more forms of a butterfly existing

under identical conditions as to climate and environment is not so

easily explained. In the case of the Gray-veined White we collect in

early spring in New England, or other Northern states, a lot of

chrysalids. We keep them until the butterflies come forth and we find

even here two distinct forms, one smaller and more delicate than the

other, with both surfaces of the wings pure white: scientists call

this form, _virginiensis_; the other larger with the under surface of

the wings slightly tinted with yellow: scientists call this form

_oleracea_. The first named has but one brood a year while the second

lays eggs which develop into caterpillars that produce butterflies of

still a _third_ form, in which the upper surface of the wings is pure

white with a slightly greater expanse: scientists call this form

_cruciferarum_. These three varieties occur in Eastern regions and may

be found in the same localities, and differ considerably from various

geographical varieties found in the Far West.

The caterpillar of the Gray-veined White is a bit smaller than those

of the nearly related forms, and in color is green with no distinct

longitudinal markings, but with many fine dots of black over the

surface. The cylindrical body is covered with a fine down. When

feeding upon cabbage it is more likely to attack the outer than the

inner leaves, and so even when abundant it is less troublesome to

gardeners than the imported species. It is now, however, so rare that

it seems to feed chiefly upon wild cruciferous plants and is more

likely to be found along the borders of open woods than in gardens and

fields. The winter is passed in the chrysalis state.

=The Checkered White=

_Pontia protodice_

Some years ago the Checkered White was commonly called the Southern

Cabbage Butterfly but the general distribution of the imported species

has had the same effect upon its abundance in the South that it has

had upon the Gray-veined White in the North. Consequently, it is now

much less abundant than formerly, even in the Southern states where it

is most at home. There are two fairly distinct forms: the spring form

and the summer form. The latter is practically of the same size as the

Imported Cabbage Butterfly: the males have the hind wings nearly white

above and the fore wings with a few black dots or spots upon their

outer halves. The females are much more definitely marked, having the

upper surface of both pairs of wings marked in black or brownish black

in such a way as to enclose a large number of white diamonds. The

spring form is decidedly smaller and the markings are much less

distinct than in the summer form.

The seasonal history of this species is comparatively simple. In

winter the chrysalids are found. From these chrysalids in early spring

the small butterflies of the spring form come forth. These lay eggs

upon various cruciferous plants which hatch into greenish caterpillars

that eat the leaves and soon mature so far as their caterpillar stage

is concerned. They are then about an inch long, with downy cylindric

bodies more or less marked with rather pale yellow stripes, touched

here and there with purplish green or dotted slightly with fine black

dots. These caterpillars now attach themselves by means of a button of

silk and a silken loop to some support like a piece of board, the side

of a stone, or almost any available shelter. Each casts its larval

skin and appears as a grayish chrysalis from which probably a

fortnight later the summer form of the butterfly emerges. There are

commonly two broods of this summer form, making three sets of

butterflies for the entire season. The caterpillars of the second

summer brood of butterflies go into the chrysalis stage in autumn to

remain throughout the winter.

Some very interesting observations upon the sleeping habits of this

butterfly have been made in St. Louis by Mr. and Mrs. Phil Rau. The

insects were found abundantly resting upon the seed heads of white

snakeroot. Early in October, when a warm south wind was blowing, the

great majority of the butterflies slept horizontally with their heads

toward the wind. At other seasons and in other places, many of them

were found in a vertical position but practically all had their bodies

toward the wind prevailing at the time. The observers were unable to

ascertain definitely whether the insects thus oriented themselves at

the time of alighting, so that their wings presented the least

resistance to the force of the wind, or whether this was a mechanical

result of the breezes.

=The Great Southern White=

_Pontia monuste_

There used to be in the Northern states before the advent of the

Imported Cabbage butterfly a familiar white butterfly which then laid

its eggs upon cabbages in much the same way that the imported pest now

does. One who has seen this northern Gray-veined White and then sees

the Great Southern White will be likely to think of the latter as a

larger edition of the former, for in the males of the southern species

the wings are practically white save for a narrow dusky border at the

outer angle of the front pair, although in the female this dusky

margin is wider and the hind wings show a series of dusky triangles

near the margin. There is also a curious black marking suggestive of a

crescent on each front wing near the middle of the front border, which

helps to make the appearance of this butterfly very distinct from that

of any other.

Although this species is at times so abundant that it swarms in great

flocks and although it has been known for many years, its life-history

seems not to have been carefully worked out since it was first

described by Abbott more than a century ago. The caterpillars feed

upon cruciferous plants and when full grown are about an inch and a

half long, of a general yellow color, more or less striped with

purple lines. The species is distinctly tropical extending northward

into our Southern states.

Dr. G. B. Longstaff reports this species as abundant in Jamaica where

he found that the clubs of the antennae of the living insects showed a

beautiful turquoise blue color, although another observer described

them as bright green with a tinge of blue. This is an interesting

color variation for a member of this group. In the tropics also there

are two forms, one belonging to the dry season and one to the wet

season.

_Synopsis of the Whites_

_Imported Cabbage Butterfly_ (_Pieris rapae_). Expanse 2 inches. Upper

surface white with a black marginal dash on the front outer angle of

the front wing. One round black spot on each of the four wings in the

male. Two round spots on each of the front wings in the female and one

round spot on each of the hind wings. Under surface of hind wings

yellowish white; spots on front wings in same position as on upper

surface. A spring form (_immaculata_) is smaller and the black spots

are almost obsolete.

_Gray-veined White_ (_Pieris napi_). Expanse 2 inches. Upper surface

white with only a darker marginal splash next the body. Under surface

white with gray veins.

_Checkered White_ (_Pontia protodice_ or _Pieris protodice_). Expanse

2 inches. Upper surface white, strongly marked especially in the

female with dark grayish brown on both pairs of wings. Along the outer

margins these marks are so arranged as to enclose white diamond spots.

Male with front wings only lightly marked and hind wings scarcely

marked at all. Under surface much like upper, with a slight yellowish

tinge in female.

_Great Southern White_ (_Pontia monuste_ or _Pieris phileta_.) Expanse

2 1/2 inches. General color white with a narrow black margin around

apical angle of front wings. These margins are wider in the female, in

which sex there is a series of marginal spots on the hind wings.

Easily known by its large size.

THE TRIBE OF THE ORANGE-TIPS

When one sees a gossamer-winged butterfly flitting from flower to

flower on a bright June day it seems one of the most ethereal of

earth's visions. One could readily fancy that the whole

sight--flowers, butterflies, and all--might easily vanish into thin

air. So it is something of a shock to hear scientists talk about

fossil butterflies and to realize that these fragile creatures have

been living generation after generation for untold millions of years.

A realization of this fact, however, helps us to understand the many

wonderful ways in which butterflies in all stages of their existence

have become adapted to the conditions of their lives.

There is perhaps no group of butterflies whose beauty seems more

fragile than that of the Orange-tips. These are delicate creatures,

with slender bodies and almost gauzy wings, of a size somewhat smaller

than our common white and yellow butterflies. Perhaps the most

remarkable feature is the marking of the wings, the upper sides of the

front pair having an orange patch near the apex and the under sides

having a background of delicate whitish or yellowish green, lined and

spotted with darker coloring in a very characteristic way. This

peculiar marking is so significant that it has been called "flower

picturing." To understand the reason for its existence one has only to

watch the butterflies in their native haunts. He will find them

flitting from blossom to blossom among the plants of the mustard

family--the _Cruciferae_. This is one of the most characteristic

families in the plant world: the foliage for the most part is small

and delicate and the flowers have a characteristic four-petaled

structure, being practically always of small size and generally toned

in whites or yellows. When an Orange-tip is at rest upon these

blossoms it merges so completely into the background that it

disappears from view. Should a bird chase one of these insects through

the air it would see chiefly the orange tips which are so marked upon

the upper side of the wing, and when the butterfly closed its wings

and lighted among the flowers the orange color would instantly

disappear and there would be only an almost invisible surface against

the background of flower and leaf.

The adaptations of these Orange-tips to the conditions of their lives

are by no means confined to this remarkable resemblance to the flowery

background. In the case of some species the whole yearly cycle has

been adapted to correspond to the yearly history of the cruciferous

food plant. As is well known many species of the mustard family spring

up early in the season, put forth their blossoms which quickly develop

into fruits and then die down, the species being carried through until

the next year by the dormant seeds. In a similar way the Orange-tips

feed as caterpillars upon the host plant through the spring,

completing their growth before the plant dies and then changing to

chrysalids which remain dormant through summer, fall, and winter and

come forth as butterflies early the following spring. The insect has

thus adapted itself in a most remarkable manner to the yearly history

of its plant host.

=The Falcate Orange-tip=

_Synchloe genutia_

The Falcate Orange-tip is about the only member of this tribe

generally distributed east of the Rocky Mountains. This is a beautiful

insect which is sparingly found even as far north as New England. It

is more abundant throughout the Southern states, occurring south at

least as far as Texas. It appears to be a good illustration of the

adaptation of its development to that of its food plants. The eggs are

laid upon leaves or stems of such spring-flowering _Cruciferae_ as

rock cress (_Arabis_), and hedge mustard (_Sisymbrium_). On hatching

the caterpillars feed upon stems, leaves, flowers, and even seed pods

of these plants, becoming mature in a few weeks and changing to

chrysalids under the protection of such shelter as they can find. In

the Northern states these chrysalids remain unchanged until the

following spring when the butterflies emerge and are found upon the

wing for a few weeks in May and early June. In some southern regions

at least the species is evidently double-brooded, as Dr. Holland

reports that he has taken the butterflies in late autumn in the

western portion of North Carolina.

[Illustration: Egg of _Synchloe genutia_, magnified 20

diameters. (From Holland)]

This Falcate Orange-tip is one of the daintiest and most exquisite of

northern butterflies. It is a prize which any collector will find joy

in possessing. It is easily recognized by its general white color,

which in the female is relieved only by a distinct black mark on the

upper surface of the front wings and a row of marginal markings upon

all the wings. The male is slightly smaller and is at once known by

the orange blotch on the outer angle of the upper surface of the front

wing. This outer angle projects into a distinct point which gives the

species its name Falcate. (_See plate, page 256._)

Dr. J. L. Hancock has described in a most interesting manner the way

in which this Orange-tip loses itself among the flowers of rock cress.

In northern Indiana he found this butterfly abundant in April at the

time of the blossoming of _Arabis lyrata_. The butterflies would be

flying about, easily seen in the air. Then they would suddenly

disappear and could be found only after the most careful search. They

had simply lit upon the flower heads, when the flower picturing of the

under surface of the wings blended perfectly with the appearance of

the clustered flower.

"The green markings of the under side of the wing," writes Dr.

Hancock, "are so arranged as to divide the ground color into patches

of white, which blend with or simulate perfectly the petals of the

clustered flowers. The eyes of the butterfly are delicate pale green

and the antennae are whitish, all of which adds to the effectiveness

of the blend. The flowers of _Arabis_ have white petals with the

centre yellowish green, as is also the calyx. There is a shade of pink

outside the base of the petals. All in all, the adaptation of insect

to flower here displayed is one of rare exquisiteness."[C]

[C] "Nature Sketches in Temperate America", p. 83.

Dr. Hancock found that the butterflies were able to cling on the

flowers during strong winds very persistently, so that even when a

storm blew across the sand dunes they were likely to remain in

position. They also have the instinct to rest very quietly after they

have lit upon the clustered flower heads.

=The Olympian Orange-tip=

_Synchloe olympia_

In various parts of the Southern states there is at least one other

Orange-tip butterfly which is found occasionally in connection with

the Falcate Orange-tip. It was named Olympia many years ago by William

H. Edwards. It is a delicate white species marked with black and

yellow very lightly both above and below, the yellow showing only on

the under side of the hind wings and that part of the front wing which

is exposed when the insect is at rest. Strictly speaking, this is not

an Orange-tip because the orange color is lacking in both sexes.

This is rather a rare species which occurs occasionally from the

Atlantic states to the Great Plains south of a line drawn from

northern Maryland to northern Missouri. Like its allies the larvae

feed upon various cruciferous plants, the hedge mustard being one of

these and the adults visit the flowers of the same family. They

doubtless have habits similar to those of the Falcate Orange-tip, and

the extreme delicacy of color must render them practically invisible

when resting upon the small white flowers of most crucifers.

[Illustration: _From a drawing by Mary E. Walker_ _See page 72_

THE TIGER SWALLOWTAIL

(Reduced)]

[Illustration: _From a drawing by W. I. Beecroft_ _See page 83_

THE IMPORTED CABBAGE BUTTERFLY

Caterpillar, chrysalis, and butterflies]

Most of the Orange-tip butterflies are found on the Pacific Slope,

ranging from Alaska southward, several of them being especially

abundant in the western mountain regions. About eight species are

recognized as belonging to our fauna, some of which have several

well-marked varieties.

_Synopsis of the Orange-tips_

_Falcate Orange-tip_ (_Synchloe genutia_, _Anthocaris genutia_ or

_Euchloe genutia_). Expanse 1 2/5 inches. Tips of front wings

projecting in a hooked angle. Orange blotch on upper surface near tip

in male, absent in female.

_Olympian Orange-tip_ (_Synchloe olympia_, _Euchloe olympia_ or

_Anthocaris olympia_). Expanse 1 1/2 inches. Wings white above in both

sexes with greenish black markings at base of all wings and along

front margin of front wings, especially at apex. No orange patch.

THE TRIBE OF THE YELLOWS

A large proportion of our most abundant and conspicuous butterflies

belong to the Tribe of the Yellows. Sometimes it is called the Tribe

of the Red-horns because the antennae of the living insects are so

often red. These insects vary in size from the large Brimstones or

Cloudless Sulphurs, expanding three inches, to the delicate little

Dainty Sulphur, expanding scarcely an inch. The distinctive

characteristics of the tribe are found in the very gradual enlargement

of the joints of the antennae that form the club, and the stout palpi,

the last joints of each of the latter being short.

=The Brimstone or Cloudless Sulphur=

_Callidrayas eubule_

Practically all northern butterflies are variously marked in different

colors, while the butterflies of tropical regions are commonly tinted

in monotone, though often showing a splendid iridescence. One with

very little experience can tell the look of a tropical butterfly and

would be likely to say at once that the Cloudless Sulphur is one of

these. The upper surface of the wings of the male is a clear plain

sulphur with merely the narrowest possible fringe of brown around the

margin made only by the colored marginal scales. The under surface is

lighter and sparsely dotted in brown. In the females the marginal

brown takes on the shape of a series of small crescents and there is a

single round brown eye-spot just in front of the middle of each front

wing.

While the Cloudless Sulphur is without doubt essentially a tropical

species it has an extraordinary geographical range. It is extremely

abundant in Mexico, Cuba, and the tropical zone in South America. It

extends south even to northern Patagonia and north to New England,

Wisconsin, and Nebraska.

Presumably in the tropics this species breeds continuously, one

generation following another in regular succession unless interrupted

by drought or other natural phenomena. In our Southern states there is

more or less interruption by the winter season, so that it is commonly

considered to have only two broods, the butterflies hibernating.

Farther north there is probably only one brood in summer, and perhaps

not even that in the extreme limit of its range. For there is pretty

good evidence that the specimens seen in the Northern states are

migrants from the south, coming singly or in scattered flocks in early

summer, and if they lay eggs the butterflies of the new generation

return south in autumn. But the precise conditions are not well known

and need careful observations in various localities.

The life-story of a generation of these butterflies is much like that

of the other Yellows. The eggs are laid, one in a place, on the

leaflets of various species of wild senna (_Cassia_) and soon hatch

into cylindrical caterpillars that devour the tender leaflets. In a

few weeks the caterpillars mature and change to curious and

characteristic chrysalids. The head projects in the shape of a cone

and the back is so concave as to give the side view of the chrysalis a

very striking appearance.

Like so many of the Yellows this butterfly is sun-loving and social in

its habits. Great numbers flock together, their large size and bright

coloring rendering them very conspicuous. They often alight on the

ground to sip moisture when they have been likened to beds of yellow

crocuses. They also fly long distances in flocks that attract much

attention. It is likely that the northward distribution takes place in

summer through such migrating hosts.

_Other Sulphur Butterflies_

The Large Orange Sulphur is a closely related butterfly of about the

same size, in which the coloring is uniformly orange-yellow instead of

lemon-yellow. It also belongs to the tropics, occurring in our extreme

Southern states and ranging occasionally as far north as Nebraska.

The Red-barred Sulphur is another splendid butterfly, somewhat larger

than the Brimstone, which is easily distinguished by the broad reddish

bar across the upper surface of the front wings. It is tropical but

migrates rarely even as far north as Indiana, Illinois, and Wisconsin.

=The Dog's-head Butterfly=

_Meganostoma caesonia_

The Dog's-head butterfly furnishes one of the most remarkable examples

of accidental resemblance in wing markings that can be found in the

whole order of scale-winged insects. It is comparable with the skull

and crossbones on the back of the death's-head moth. In the butterfly

the middle of the front wings has a broad band of yellow against a

black margin on each side and the yellow outlines make an excellent

silhouette of the profile of a poodle with a large black eye-spot in

exactly the proper place. The females are less brightly colored than

the males but they still show the dog's-head silhouette.

This is a southern species, which occasionally strays as far north as

New York City, New Hampshire, Wisconsin, and Iowa. The larvae feed on

species of Amorpha and are believed to be three-brooded in southern

regions where the butterfly occurs.

The California Dog's-head is even more beautiful than the southern

species. It is remarkable for its pink and purple iridescence--a

characteristic which is not common in the butterflies of the Yellow

and the White Tribes. The silhouette of the Dog's-head is less perfect

than in the more eastern species, and the yellow color tones are more

tinged with orange. The female is strikingly different, the wings

being plain pale yellowish buff marked only with a round blackish

eye-spot near the middle of each front wing and the barest suggestion

of a dark line around the extreme margin.

=The Clouded Sulphur=

_Eurymus philodice_

It is an interesting fact that the butterfly which one is most likely

to find in fields and along roadsides during practically all the weeks

of summer has seldom if ever been noted as a destructive insect. The

Clouded Sulphur is probably the commonest species in its group. There

may be times when the White Cabbage butterfly or other forms are more

abundant, but the Clouded Sulphur retains its place season after

season, with comparatively little noticeable variation in its numbers.

This is doubtless an illustration of an insect which has established

such relations with its food plants and its various insect and other

enemies that it remains in a fairly stable equilibrium--an example of

what is often called the balance of nature.

The Clouded Sulphur is about the only medium-sized yellow butterfly

generally found in the Northeastern states. The adults may be seen

from spring until autumn. They lay eggs upon clover and other plants.

These eggs hatch into small green caterpillars that feed upon the

leaves and are protectively colored so they are comparatively seldom

seen. When the food plant is disturbed they drop to the ground,

crawling up again upon stems and leaves when the disturbance is over.

These caterpillars moult several times during their growth. When full

grown they find such shelter as they are able and each spins a silken

web over part of the surface. It then fastens its hind legs into this

web and later spins a loop near the front end of the body. It pushes

itself beneath this loop and waits for several hours before the skin

breaks open along the back and is gradually shuffled off revealing the

chrysalis in position. A week or two later the fully developed

butterfly emerges from the chrysalis.

These yellow butterflies lend a distinctive charm to our summer

landscapes. They are constantly to be seen fluttering from place to

place, lightly visiting flowers of many kinds from which they suck the

nectar, and gathering in great colonies by roadside pools where they

seem to sip the moisture. There are many references to this insect in

the writings of New England authors. It evidently was an especial

favorite of James Russell Lowell who has often referred to it in

passages like this:

"Those old days when the balancing of a yellow butterfly over a

thistle bloom was spiritual food and lodging for a whole forenoon."

=The Orange Sulphur=

_Eurymus eurytheme_

Were one able to take a Clouded Sulphur butterfly and change the

yellow to a deep orange color he could easily make a specimen that

would pass for the present species. The resemblance is very

remarkable and shows the close affinity between these two beautiful

insects.

Like so many others of this group the Orange Sulphur is essentially a

tropical species. In the eastern United States it is rarely found

north of latitude forty degrees, but south of that it becomes

increasingly abundant as one approaches the tropics. It occurs from

the Carolinas to Texas, and over the great range in which it lives it

takes on many different forms and habits. It is one of the most

remarkable examples of variation in coloring exhibited by any of the

butterflies. Nearly a dozen species names have been given to its

various disguises, all of which are now recognized as synonyms. In the

more northern regions where it is found, only one of these forms

usually occurs, but in other places bright yellow and pale white

varieties are found.

The life-history of this butterfly along latitude forty degrees is

very similar to that of the Clouded Sulphur. There seem to be usually

two broods and the caterpillars live upon leguminous plants,

especially alfalfa, buffalo clovers, wild senna, and other species of

Trifolium and Cassia. Apparently also it hibernates in both the

caterpillar and the butterfly stages.

In the extreme Southwest--as on the plains of Texas--the vegetation

dries up completely in summer so that there is no succulent leafage

for the caterpillars to live upon. In such cases the insect must

aestivate rather than hibernate. This species apparently succeeds in

doing this by having the caterpillars go into a more or less lethargic

condition in which they pass the summer. The adult butterflies utterly

disappear in June and are not seen again until early in autumn when

the autumn rains have started the growth of vegetation anew. The

insects then make up for lost time and produce several broods in rapid

succession.

In the Imperial Valley of California this butterfly is a serious pest

to alfalfa growers. It continues to reproduce throughout a very long

season, one brood following another from March until December, and in

mild winters there seems sometimes to be practically no cessation of

its activities. Mr. V. L. Wildermuth found that the development of a

generation in breeding cages in this valley varied from twenty-two to

forty-four days, the latter in cool, the former in hot weather. The

stages in the first and the third broods in spring varied thus: Egg,

first six days, third four days; larva, first thirty days, third

twelve days; chrysalis, first eight days, third five days. In this

case the first generation extended from March 15 to April 30 and the

third from May 28 to June 20. After the fourth brood of butterflies

there was such an overlapping of the various stages that it was

impossible to distinguish the broods.

=The Pink-edged Sulphur=

_Eurymus interior_

This beautiful butterfly was first made known to the world of science

by Louis Agassiz, the great naturalist who did so much to arouse a

scientific interest among Americans. He found it on a famous

expedition to the northern shores of Lake Superior, which not only

served to bring to light many interesting phases of geological history

but also laid the foundation for the copper mining industry which has

since become so important in that region. The butterfly thus brought

to light has been found to be a characteristic northern species,

occupying a rather narrow belt nearly along the fiftieth degree of

latitude and extending west almost to the Pacific Coast. The species

is occasionally taken as far south as the White Mountains and there

are indications that in this region there are two broods a year. The

male butterflies are known at once by a beautiful pink edge on all the

margins; they bear otherwise a close resemblance to our common Sulphur

Yellow. The females are much lighter in color, often having no black

markings on the upper surface of the hind wings.

=The Black-bordered Yellow=

_Eurema nicippe_

This is essentially a tropical butterfly which has spread out over

most of our Southern states where it is abundant and widely

distributed. It adds a distinct touch of color and life to many

landscapes when the butterflies swarm by thousands upon clover

blossoms and other low vegetation. The eggs are laid upon the leaves

of clover and more especially upon some common species of Cassia, such

as wild senna. Each egg soon hatches into a small greenish cylindrical

worm, colored and striped in such a way that as it rests upon the leaf

it is easily overlooked. This larva develops rapidly and soon becomes

about an inch and a quarter long, being rather slender and fairly

smooth. It now spins a bit of silk upon a twig or some similar support

and also the frailest sort of a silken loop to pass around its back.

It now entangles its hind feet in the bit of silk and soon casts off

its last caterpillar skin, emerging as a curious looking chrysalis

about three quarters of an inch long with a remarkable pointed

projection on the front of the head. When seen through a hand lens

this pointed projection and the well-developed characteristic wing

sheaths give the chrysalis a remarkable resemblance to some of the

twig hoppers or Membracids. The colors vary considerably with the

surroundings but are commonly toned in various shades of green and

yellow brown.

A little later each chrysalis breaks open to disclose one of the

beautiful butterflies.

The conditions under which this butterfly lives at the limit of its

northern range are not well determined. It is probable that many of

those seen here have flown from considerably farther south, and that

these migrants lay eggs from which a brood of butterflies develops,

these native born appearing late in summer. Presumably the latter

hibernate, but whether they can do this successfully under the

rigorous conditions of our northern winters has never been determined.

In fact, Scudder wrote some years ago that no caterpillars had ever

been found in New England. Here is an interesting opportunity for some

young observer to make a real contribution to science.

=The Little Sulphur=

_Eurema lisa_

Were one to imagine a Clouded Sulphur butterfly reduced to half its

usual size and built with a corresponding delicacy of structure, one

would have a pretty good idea of the beautiful little creature called

by the above name. I well remember in my college days taking what was

probably the first of these butterflies ever collected in the region

of our Michigan college. It was a prize that very likely had wandered

north from Indiana but which served to add much glory to the little

collection in which I took such pride, for this is essentially a

southern species. In many regions of the South it is so abundant that

it can be taken by any one. It ranges from coast to coast and extends

south into the tropics. In the eastern region it is found from

southern Wisconsin to southern New England, occurring sparingly and

locally in various places along the line thus indicated.

The food plant of the species is chiefly wild senna or other kinds of

Cassia. The mother butterflies deposit the eggs singly on leaves or

stems, generally on the small leaflets of the compound leaf. Less than

a week later each egg hatches into a cylindrical greenish caterpillar

that feeds upon the leaflets in a characteristic fashion. Instead of

devouring the blade from the margin inward it gnaws narrow strips

between the smaller veins. When not feeding, the caterpillars protect

themselves from observation by birds or other enemies by resting

motionless along the stem of the leaflet or else along the midrib on

the under side. As is well known the leaflets of Cassia, like other

leguminous plants, close at night. It is probably on this account that

these caterpillars feed chiefly by day. The general green color of the

skin and the straight stripe along the side help to make this

caterpillar very inconspicuous when it is at rest.

When full grown the caterpillar reaches a length of three quarters of

an inch. It now finds some bit of shelter on which it spins a bit of

flat web and a silken loop to hold it in place as it becomes a

chrysalis. It then changes and remains quiescent for ten days or more

when it emerges as the dainty butterfly.

Notwithstanding its abundance and its successive broods its

life-history is none too completely worked out. There is still

opportunity for careful observations upon the way in which it passes

the winter in various parts of its range. While in the South it

apparently hibernates as an adult, this fact is not certain in the

more northern localities.

Notwithstanding its diminutive size this butterfly has been known to

swarm in such enormous numbers as to seem a veritable cloud. The most

notable record of this has been quoted by Scudder in connection with a

swarm that invaded the Bermuda Islands, in 1874, on the first day of

October. It was described in these words:

"Early in the morning several persons living on the north side of the

main island perceived, as they thought, a cloud coming over from the

northwest, which drew nearer and nearer to the shore, on reaching

which it divided into two parts, one of which went eastward and the

other westward, gradually falling upon the land. They were not long in

ascertaining that what they had taken for a cloud was an immense

concourse of small yellow butterflies, which flitted about all the

open grassy patches in a lazy manner, as if fatigued after their long

voyage over the deep. Fishermen out near the reefs, some few miles to

the north of the islands very early that morning, stated that numbers

of these insects fell upon their boats, literally covering them."

As is the case with so many of the related yellow butterflies there is

an albino variety of this species. It has been given the variety name

_alba_ although it is really a pale yellow rather than a true albino

form.

=The Dainty Sulphur=

_Nathalis iole_

While the Little Sulphur butterfly seems about as delicate a creature

as one could ask to see, it loses that distinction when it is compared

with the still smaller Dainty Sulphur. The latter expands scarcely an

inch when its wings are stretched apart, and its slender body and

antennae help to give the suggestion of extreme delicacy. There is

more marking of black upon the sulphur-yellow wings than is the case

with the larger form, the upper portion of the front wings showing

only a broad yellow band upon a background of darker color. The under

wings are nearly all yellow.

_Synopsis of the Yellows_

_Brimstone_ or _Cloudless Sulphur_ (_Callidryas eubule_ or

_Catopsilia eubule_). Expanse 2 1/2 inches. Upper surface of male

clear, light, sulphur yellow. Female with a brown spot in front of

middle of each front wing and a narrow brown margin on all the wings.

Under surface deeper yellow with sparsely scattered brownish dots.

_Red-barred Sulphur_ (_Callidryas philea_ or _Catopsilia philea_).

Expanse 3 inches. Easily known by the reddish orange bars on the

sulphur-yellow wings.

_Large Orange Sulphur_ (_Callidryas agarithe_ or _Catopsilia

agarithe_). Expanse 2 1/2 inches. Distinguished at once by its uniform

orange-yellow color.

_Dog's-head Butterfly_ (_Zerene caesonia_, _Colias caesonia_ or

_Meganostoma caesonia_). Expanse 2 1/4 inches. Upper surface yellow

with black inner and outer borders on front wings and black outer

border on hind wings. The black and yellow of each front wing so

combined as to make a distinct dog's head with black eye.

_Clouded Sulphur_ (_Eurymus philodice_ or _Colias philodice_). Expanse

2 inches. Upper surface sulphur yellow with blackish borders, the

yellow brighter in the male than in the female. Male with line between

yellow and black distinct, a black spot just in front of the middle of

each front wing and an orange spot near the middle of each hind wing.

Under surface of male deeper yellow, with spots as on the upper

surface but without black margin, and with a row of sub-marginal

brownish dots on each wing. Female with upper surface more generally

suffused between marginal mark and the yellow part with more or less

duskiness both above and below. Spots on each wing much as in male. In

the white form of the female (_pallidice_) the yellow is replaced by

white.

_Pink-edged Sulphur_ (_Eurymus interior_). At once distinguishable

from _philodice_ by the narrow pink edge of all the wings, showing

both from above and from below, slightly smaller as a rule.

_Orange Sulphur_ (_Eurymus eurytheme_ or _Colias eurytheme_). Expanse

2 1/4 inches. Much like Clouded Sulphur in markings except that

prevailing color-tone is orange yellow.

_Black-bordered Sulphur_ (_Eurema nicippe_, _Xanthidia nicippe_ or

_Terias nicippe_). Expanse 2 inches. Upper surface of wings bright

orange with a small black dash in front of the middle of each front

wing and a broad black border on all the wings. In the females the

borders are interrupted at the rear. Under surface slightly brownish

yellow, minutely striated and clouded when exposed when the butterfly

alights.

_Little Sulphur_ (_Eurema euterpe_, _Eurema lisa_, _Xanthidia lisa_ or

_Terias lisa_). Expanse 1 inch. Easily known by its small size and

delicate structure. Upper surface of wings yellow with distinct black

borders. Under surface yellow with indistinct spots.

_Dainty Sulphur_ (_Nathalis iole_). Expanse 1 inch. Easily known by

its small size and narrow yellow wings with black bars across the

outer angles and black bands across the back border of the front wings

and the front border of the hind wings.

THE NYMPHS

FAMILY _Nymphalidae_

A large proportion of our most familiar butterflies belongs to this

family. The Fritillaries, the Angle-wings, the Sovereigns, and the

Emperors are tribes in which practically all the species are of medium

or large size. The Crescent-spots include a few which are rather

small.

The combinations of characters by which the Nymph family is

distinguished are these: Front legs dwarfed into lappets; scaly

antennae; veins of fore wings not swollen at base; wings of normal

shape, not much longer than wide. Larvae cylindrical, but varying

greatly in form, color, and skin coverings. Chrysalids angular in

most species, in others rounded.

The stories of the lives of the many members of this family vary

considerably, as one would expect from their variety and numbers. We

may take, however, the life of the familiar Antiopa or Mourning Cloak

as typical of the group. Briefly summarized, its story may thus be

told:

During sunny days in spring one may often see a beautiful purple-back

butterfly, having a cream-colored border along the outer margin of its

wings, flying leisurely about, in the vicinity of woods and in the

open fields. This insect is called the Antiopa or Mourning Cloak; it

is represented natural size in plate opposite page 145. It has passed

the winter in this adult condition, having found shelter in some

retreat where it is not directly exposed to the storm and stress of

the weather.

When the leaves of the elm, willow, and poplar trees are nearly

expanded, these butterflies deposit their eggs upon the twigs. These

eggs are laid in clusters encircling the twigs, there being twenty or

more in each cluster. In the act of oviposition, the butterfly keeps

her wings spread out, moving the body and abdomen about as the placing

of the eggs necessitates.

About two weeks after the clusters of eggs are thus laid upon the

twigs of the food plant, they hatch into small blackish caterpillars,

each emerging from the egg shell through a small hole that it eats out

of the upper surface. They thus enter upon the second stage in their

life-history--the larva or caterpillar stage. As soon as hatched, they

crawl to the nearest leaf upon which they range themselves side by

side, with their heads toward the margin of the leaf. They feed in

this position, nibbling at the green surface of the leaf-blade and

leaving the network of veins untouched.

[Illustration: _See page 76_

THE ZEBRA SWALLOWTAIL

Summer form: upper surface, above; under surface, below]

[Illustration: _From a drawing by Mary E. Walker_ _See Page 101_

THE CLOUDED SULPHUR BUTTERFLY

Caterpillar and butterfly on red clover plant. (Reduced)]

[Illustration: _From a drawing by Mary E. Walker_ _See page 76_

ZEBRA SWALLOWTAILS

Visiting blossoming branches of the pawpaw tree. (Reduced)]

[Illustration: _See pages 97-115_

SOME OF THE TRIBE OF YELLOWS

upper surfaces at left; under surfaces at right

(1) The Black-bordered Yellow--male;

(2) the Clouded Sulphur--male;

(3) the Orange Sulphur--female;

(4) the Dog's-head--male]

These caterpillars continue to feed in this manner for about a week,

remaining side by side when feeding, and marching in processions from

one leaf to another as the food supply is exhausted. Wherever they go,

each spins a silken thread on the surface traversed, so that the

combination of all the threads makes a sort of carpet that serves as a

foothold for the caterpillars. At the end of the week they moult or

cast their skins, a process in which the skin of each larva splits

open along the back, and the larva crawls out covered with a new skin

that had been formed beneath the old one. This new skin stretches

somewhat after the caterpillar emerges, so that the insect is able to

increase considerably in size. At the period of moulting, the

caterpillars remain quiet for a short time, but they soon become

active again and begin feeding with increased voracity.

[Illustration: Eggs of Mourning-Cloak, laid in a cluster on a

twig. (From Holland).]

During the next three weeks, this moulting process is repeated three

times, the caterpillars becoming larger each time, and leaving their

cast skins upon the denuded twigs. They soon scatter more or less over

neighboring leaves, but remain in closely associated colonies. As they

increase in size, they eat more and more of the leaf substance; when

half grown, they devour all but the midrib and the side veins; but

when they get larger, only the midribs are left.

The carpet web that they form becomes more conspicuous as the

caterpillars become full grown. They then leave the tree or shrub on

which they have been feeding, and scatter about, seeking some

sheltered situation. Having found this--perhaps beneath a stump or

along the under side of a fence--each caterpillar spins a web of silk

along the surface. It then entangles the hooked claws of its hind legs

in the silken web, and lets its body hang vertically with the head end

curved upward. It remains in this position some hours before the skin

along the back just behind the head splits apart and is gradually

wriggled upward, until finally it is all removed and there hangs in

place of the caterpillar a peculiar object having no definite form.

But it rapidly assumes a definite form--that of the chrysalis--which

is grayish brown, different specimens varying somewhat in shade.

In this quiet chrysalis, the insect is apparently almost as inert as a

mummy. If you touch it it will wriggle a little, but otherwise it

hangs there mute and helpless. On the inside, however, the tissues are

being made over in such a wonderful way that, in about two weeks, from

the mummy case into which the caterpillar entered there comes a

beautiful butterfly.

When this butterfly first breaks through the mummy shell, its wings

are very small, although its body, antennae, and legs are well

developed. By means of the latter, it clings to the empty chrysalis,

while its wings expand. At first these wings are short, but as soon as

the insect takes a position in which the wings hang downward, they

begin to expand, and soon reach full length, but are more or less

crumpled longitudinally, and the front wings are not so wide as the

hind ones, hanging limply inside the latter.

After the butterfly has thus reached its full form and size, it crawls

from the chrysalis to some neighboring support, where it rests quietly

for half an hour or more. During the latter part of this time it

exercises its unused muscles by slowly opening and closing its wings,

until it finally flies away.

THE TRIBE OF THE FRITILLARIES

This is one of the most distinctive tribes of the family of Nymphs.

The clubs of the antennae are about twice as long as broad and

curiously spoon-shaped. The palpi are large and bushy, with the last

joint very short. Most of the species are rather large and practically

all are beautifully mottled in various tones of brown, red, black, and

silvery gray. A large proportion of our midsummer butterflies are

members of this tribe.

=The Gulf Fritillary=

_Agraulis vanillae_

In tropical America there is a genus of butterflies called Agraulis.

These are fairly large insects, approximating the size of the Viceroy,

which show most beautiful colors in the tropical sunshine. One member

of this genus has come north to our Southern states, and is

occasionally found as far up as Virginia and southern Illinois,

extending below this from ocean to ocean. It reveals on its upper

surface the most exquisite tints of iridescent purples and browns,

suggesting by its form and color as thus seen a tropical species. The

lower wing surface, when the wings are closed in their natural

position, shows only a spangled effect of silver-white and brown,

which is very suggestive of the under surface of our northern Spangled

Fritillaries. So this beautiful species may fittingly be called the

Gulf Fritillary, carrying over from the north some of its peculiar

beauty and connecting with the equally distinctive beauty of the

tropical south.

Like so many other southern butterflies the eggs of this species are

laid upon the leaves of passion vines. The caterpillars develop very

rapidly and when matured are yellowish or brownish yellow, striped

with darker lines along the back and sides. There are black branching

spines, arranged in rows beginning on the head and running backward on

the body. The whole cycle of life from egg to butterfly may take place

within the short period of a month and one brood succeeds another in

so irregular and rapid a fashion that it is difficult to determine

definitely the number of broods in a season.

=The Variegated Fritillary=

_Euptoieta claudia_

There is something in the appearance of the upper surface of this

butterfly that suggests the other Fritillaries on the one hand and the

Emperors on the other. The coloring and marking is a bit like the

former and the shape of the wings like the latter. The general color

is a golden brown with darker markings arranged in bands and eye-spots

in a rather complicated pattern. The under surface, so far as it is

exposed when the butterfly is at rest, is a beautiful marbled

combination of gray and brown which is probably distinctly

obliterative in the haunts of these insects. The front wings have the

outer margin concave in the middle, giving a special prominence to the

shape of each front outer angle.

This butterfly is a southern rather than a northern species, but it is

found occasionally from Montana to Massachusetts and southward to

Arizona, Mexico, and Florida. Even in northern Indiana it is very

seldom found and is considered rare in the southern part of that

state. Around Buffalo, New York, it is also rare and is not common in

the vicinity of New York City. In the more Southern states, however,

it is abundant and extends well through the continent of South

America.

There is considerable evidence to indicate that this butterfly

hibernates as an adult. In the more southern regions it probably also

hibernates in other stages, especially the chrysalis and the larva. In

regions where it is double-brooded, as it appears to be in the

latitude of New York City, the seasonal history seems to run something

like this: the partly grown caterpillars which have passed the winter

in shelter at the surface of the soil feed upon the leaves of violets

and certain other plants. They change to chrysalids, probably in May,

and emerge as butterflies in June. These butterflies lay eggs for a

summer brood of caterpillars which may feed upon the leaves of

violets, May apples, portulaca, and stonecrop. They grow into

cylindrical worms of a general reddish yellow color, marked by

longitudinal stripes of brown upon the sides and a row of whitish dots

upon the back. They become matured in time to disclose the butterflies

of the second brood in August and September. Presumably these

butterflies lay eggs that develop into caterpillars which hibernate

when partially grown.

Farther south there are probably three broods a year and hibernation

may take place in various stages. There is good opportunity for

careful work in determining the life-history of the species in

different latitudes. The butterfly is found in much the same

situations as the other Fritillaries, flying over meadows and along

the borders of woods.

=The Diana Fritillary=

_Argynnis diana_

This magnificent butterfly differs from the other Fritillaries in the

fact that the females are so unlike the males that only a skilled

naturalist would even guess that they are related. Both sexes are

rather rare and are found only in a comparatively narrow range

extending from West Virginia to Missouri, northward to Ohio and

Indiana, and southward to Georgia and Arkansas.

This species was first described by Cramer a long time ago from

specimens of the male sex. It was later described by Say and other

writers all of whom saw only the males. The other sex was first

recognized by William H. Edwards, whose account of its discovery as

given in his splendid work on the Butterflies of North America is

worth quoting:

"No mention is made of the female by any author," wrote Mr. Edwards,

"and it seems to have been unknown till its discovery by me in 1864 in

Kanawha County, West Virginia. On the 20th August, I saw, for the

first time, a male hovering about the flowers of the iron-weed

(_Vernonia fasciculata_), and succeeded in taking it. Two days

afterwards, in same vicinity, while breaking my way through a dense

thicket of the same weed, hoping to find another Diana, I came

suddenly upon a large black and blue butterfly feeding so quietly as

to allow me to stand near it some seconds and watch its motions. It

seemed to be a new species of Limenitis, allied to Ursula, which it

resembled in color. But on taking it, I saw it was a female Argynnis,

and the general pattern of the under wing left little doubt of its

affinity to the Diana male, despite its total difference in color and

of upper surface. Subsequent captures confirmed this conjecture, and

out of the large number that have since been taken the males have been

of the known type and the females black, with no tendency in either to

vary in the direction of the other.

"When my attention was called to the species I found it not very

uncommon, always upon or near the iron-weed, which is very abundant

and grows in rank luxuriance upon the rich bottom lands of the Kanawha

River, frequently reaching a height from eight to ten feet and in

August covered by heads of purple flowers that possess a remarkable

attraction for most butterflies. Both sexes are conspicuous, the males

from the strong contrast of color and the females from their great

size and the habit of alighting on the topmost flower and resting with

wings erect and motionless. It is an exceedingly alert and wary

species, differing in this from our other Argynnids. At the slightest

alarm it will fly high into the woods near which, upon the narrow

bottoms or river slopes, it is invariably found. It is a true southern

species, sensitive to cold, not to be looked for in the cooler part of

the morning but flying down from the forest when the sun is well up.

From eleven to three o'clock is its feeding time."

The life-history of this fine butterfly is similar to that of the

lesser Fritillaries. The butterflies appear from midsummer onward, the

males preceding the females, and the eggs are laid on or near violets

in August or September. The larvae hibernate and mature early the

following summer. As they approach the chrysalis stage they are rather

large velvety black caterpillars with brown heads and rows of fleshy

barbed spines that show an orange tint at their bases. There is thus

but one generation each year.

=The Regal Fritillary=

_Argynnis idalia_

The Regal Fritillary, fresh from the chrysalis, still showing the

marvelous sheen of its iridescence, furnishes one of the most

beautiful exhibitions of color in the world of nature. Over the whole

wing surface there are tiny scales that reflect the sunlight in an

almost dazzling manner, giving a distinct purplish tone especially to

the hind wings.

The Regal Fritillary is one of the largest butterflies of the

distinctive group to which it belongs. The wings expand some three

inches and the rather thick body is more than an inch long. The

general ground color of the wings is brown, with distinct markings of

blackish which in the hind wings almost obscure the brown. On each of

the latter as seen from above there is a distinct row of cream-colored

spots across the middle, duplicated by a similar row of brown spots

near the margin. The under surface of both pairs of wings is much

lighter and thickly mottled all over with light cream-colored spots of

a large size and more or less triangular shape. (_See frontispiece._)

Like the other Argynnids, the Regal Fritillary is single-brooded

during the year and it has a rather remarkable longevity in each stage

of its life. The newly hatched caterpillars go into hibernation and

live through the winter without feeding, finding shelter at the

surface of the ground, especially beneath the leaves of violets which

form their chosen food plants. When the snow has disappeared and the

warmth of the spring sun brings them out of their winter lethargy

these tiny caterpillars feed upon the violet leaves and grow slowly

for several weeks. They then change to chrysalids, the time for doing

this varying considerably with the individual and doubtless with the

warmth of the situation in which each is living. The length of time

spent in the chrysalis varies also, but in general it seems to be less

for those which develop into male butterflies than for the females. It

is a curious fact that the former may be found for nearly two weeks

before any of the latter appear.

The first butterflies of this species are usually disclosed from the

chrysalis late in June or early in July. They continue to come forth

for several weeks, apparently until nearly the middle of August. They

lead a leisurely life, visiting freely the flowers of goldenrod,

iron-weed, boneset, Joe Pye weed, and especially swamp milkweed. They

are most likely to be found in lowlands and along the borders of

swamps where these favorite flowers are growing. It evidently requires

some time for the eggs to develop within the ovaries, for the

butterfly cannot begin laying these until the latter part of August.

They apparently are normally deposited on the under side of violet

leaves, although so far as I know no butterfly has been seen thus

laying her eggs. It would be an interesting point for some young

observer to determine. Even the eggs take a long time to develop, not

hatching for three or four weeks after they are laid. When they do

hatch the tiny caterpillars seem not to eat at all but to go directly

into hibernation.

These butterflies are to be found in their preferred habitats almost

any time during July, August, and September. Apparently many of them

live as adults for nearly three months so that whether we consider the

egg, the larva, the chrysalis, or the adult we have in this species an

unusual duration of life. This is doubtless an adaptation to the fact

that the species must get through the year with only one brood.

This unity of habit with no such variations as occur in many

butterflies with a wider range north and south is apparently

correlated with the distribution of this butterfly. It is found in a

belt of territory running from New England and the Atlantic states

westward at least to Nebraska along a line which approximates the

annual isotherm of fifty degrees Fahrenheit.

=The Great Spangled Fritillary=

_Argynnis cybele_

To one who wanders much in the woods and open fields there are few

summer scenes more characteristic of the season than that of a group

of milkweeds in full flower, surrounded by a host of brown butterflies

busily sucking the nectar from the curious pink blossoms. There are

likely to be several species of these winged creatures, but in many

regions of America the largest and most conspicuous will generally be

the Great Spangled Fritillary. This butterfly is easily recognized by

its large size and its combination of two colors of brown, with

whitish or silverish spots scattered over the lower surface of the

wings.

The life-history of this insect is of peculiar interest on account of

the way in which it passes the winter. The mother butterfly remains

upon the wing through many weeks in summer, so that toward the end of

August or early September a large proportion of the specimens have a

decidedly frayed appearance. They are patiently waiting for the season

of the year when they can deposit their eggs, apparently knowing by

instinct that this must not be done until early autumn. When the

proper season arrives they lay their eggs upon the leaves or stems of

wild violets, apparently without much reference to the particular

species. Sometimes they have been reported simply to drop the eggs

loosely upon the violet plant with no attempt to fasten them in place.

Having thus deposited the eggs the mother butterflies soon die.

It would not seem strange if these eggs remained unhatched until the

following spring, but the fact is that the eggs hatch very soon into

small caterpillars that eat off part of the shells in order to escape

and sometimes eat also part of the shell remaining after they have

emerged. Various good observers have apparently established the fact

that these tiny caterpillars eat nothing else before winter sets in.

It seems curious indeed that they should not nibble at the leaves or

stems of the violet plants in order to be slightly prepared for the

long fast that awaits them before they will find food upon the young

buds the following spring. The case is somewhat similar to that of

the common tent caterpillar which becomes a fully formed caterpillar

within the egg shell before the end of autumn, but remains unhatched

until the following spring. In the present case the caterpillar

hibernates outside of the egg shell rather than within it.

When at last the warm sunshine of spring starts the violets into new

growth the tiny caterpillars begin feeding upon the succulent tissues.

They nibble away day after day for a week or more before they become

so large that they have to cast their skin for the first time. They

then feed again and continue this process of feeding and moulting

until early in summer. They are likely to hide themselves during

daylight and have the reputation of being difficult to rear under

artificial conditions.

The full-grown caterpillar wanders along the surface of the ground in

search of suitable shelter for the chrysalis period. When it comes to

a large stone with sides projecting more or less horizontally or a log

lying upon the ground or even a large piece of loose bark it is likely

to stop and change to the pupa or chrysalis. In this condition it is

dark brown in color and well covered with thickened tubercles,

especially along the back of the abdomen.

About a fortnight later the chrysalis breaks open and the fully

developed butterfly comes forth. It rests quietly for a time while its

wings expand and the tissues harden and then sallies forth for its

long period of flight; for this insect is single-brooded in the

Northern states at least and the butterflies that thus mature late in

June or early in July are likely to remain alive until early in

September. So they have a comparatively long life for a butterfly that

does not hibernate as an adult.

=The Silver-spot Fritillary=

_Argynnis aphrodite_