In this order the importance of collecting the early states and of
rearing the adult insects rather than of catching the latter should, if
the collector has the advancement of knowledge and the greatest pleasure
in mind, be insisted upon. Collected specimens, in the majority of
cases, will be more or less rubbed or damaged and unfit for permanent
keeping, and will always be far inferior to freshly reared specimens.
All Lepidopterists, therefore, rely to a great extent upon breeding
rather than upon field collecting. There are, however, many species of
which the early states are still unknown, and these can only be taken by
field collecting, and by attracting to various lights or traps. This
subject, therefore, naturally falls into two categories--(1) the general
collecting of the adult, and (2) collecting the early stages and rearing
the perfect insects.
[Illustration: FIG. 70.--The Eight-spotted Forester (_Alypia
octomaculata_). _a_, larva; _b_, enlarged segment of same; _c_, moth.]
_Collecting the Adult._--The implements for the general collecting of
butterflies comprise the collecting net, and in some cases the beating
net, although the use of the latter will not often be called for. The
Rhopalocera or Diurnals may be taken about flowers, and the best season
is in the early spring. Most of them are double-brooded, and the second
brood will be in the greatest abundance during July and August. They
are, however, to be found throughout the summer. They are also to be
looked for in the neighborhood of the food-plants of their larvae, and in
the case of many species, examination of such plants affords the most
satisfactory means of collecting. The food of butterflies is almost
exclusively the nectar of flowers, but strangely enough they are also
attracted to decaying animal matter, and many species, including rare
forms, may be taken about decaying animal matter or resting on spots
where dead animals have lain, or beneath which they have been buried.
Moist spots of earth are also frequented by them, especially in dry
seasons. Many of the larger butterflies, whose larvae feed on the taller
shrubs and the foliage of trees, will be found fluttering about the open
spaces in forests, but by far the larger number, as the Browns, the
Blues, the Yellows, and the Whites, which develop on the lower
herbaceous and succulent plants, will be found flying over fields,
prairies, and gardens. Crepuscular and nocturnal Lepidoptera, comprising
most of the Heterocera, the Sphingidae, Bombycids, Noctuids, etc., have
different habits. The Sphingidae or Hawk Moths fly in early evening, and
may be collected in quantity about such plants as the Honeysuckle,
Thistle, Verbena, Petunia, etc. The Bombycids and many Noctuids also fly
in the early evening, but mostly at night. The former, however, do not
frequent flowers, except such as are the food-plants of their larvae, as
their mouth-parts are rudimentary, and they take no nourishment.
[Illustration: FIG. 71.--Collecting Pill-box. _a_, glass bottom
(original).]
Collecting by the aid of strong light is a favorite means for moths as
well as other insects, and nowadays the electric lights in all large
cities furnish the best collecting places, and hundreds of species may
be taken in almost any desired quantity. In woods or in other situations
they may be attracted to a lantern or to a light placed in an open
window. Various traps have been devised, which comprise a lamp with
apparatus for retaining and stupefying the insects attracted to the
light. The common form is made by providing a lantern with a strong
reflector. Under the light a funnel several inches larger than the
lantern reaches down into a box or bottle containing the fumes of
chloroform, ether, or benzine.
[Illustration: FIG. 72.--Method of holding and manipulating collecting
pill-box in capturing (original).]
Mr. Jerome McNeill describes at length and figures in the _American
Naturalist_, Vol. XXIII, p. 268-270, an insect trap to be used in
connection with electric lights. It consists of a tin pail or can
charged with cyanide after the manner of a collecting bottle, which is
attached beneath the globe of the electric light.
The insects attracted by the light strike against a vertical tin screen
fixed above the can and fall into a tin funnel the small end of which
enters and closes the mouth of the can, and they are thus conducted into
the last. A support or post in the center of the can bears a hollow tin
cone, the apex of which is pierced with a number of small holes to admit
light, and enters and partly closes the lower end of the funnel. The
entire interior of the can is painted black and the chief light comes
through the holes in the apex of the interior cone. The entrapped
insects endeavor to escape by crawling up the central post towards the
light coming through the small holes in the end of the cone rather than
by the entrance slit about the latter and fall back repeatedly until
overcome by the cyanide.
Many of the Lepidoptera will be ruined by the beetles and other insects
or by their own ineffectual attempts to escape, but Coleoptera,
Hymenoptera, Neuroptera, and Hemiptera are secured in satisfactory
condition.
Many of the devices are very complicated and can not be described in
this connection. The nocturnal species, also, fly into our houses, and
this is especially the case in the country, and an open window, with a
strong light reflected onto a table covered with either a white paper or
a white cloth will keep one busy, on favorable nights, in properly
taking care of the specimens thus attracted.
Another favorite method of collecting moths early in the evening, or as
late as or later than midnight, is by sugaring. This consists in
smearing a mixture of sugar and vinegar, or some similar compound, on
the bark of trees or on the boards of fences, and visiting the spot from
time to time to collect the moths attracted to the bait. It has been
found that the use of beer or some other alcoholic liquor, as rum or
brandy, with the sugar or molasses water, greatly adds to its efficiency
in attracting the moths. This method of collecting moths will be found
especially efficient on warm, moist, cloudy nights. The collector should
be provided with a dark lantern and a good net, and a number of
wide-mouthed cyanide collecting bottles. The smearing should be done
just before dark, and I have always found that better success attends
this method of collecting when two are engaged in it--one to hold a
bull's eye lantern while the other bottles the specimens. Experience
will soon teach the surest way of approaching and capturing the
specimens.
For collecting Microlepidoptera, in addition to the ordinary net, some
special apparatus will be found very essential. Lord Walsingham makes
use of a special glass-bottomed pill-box, with which to capture
specimens, and the satisfactory nature of the work done with this box,
and the dexterity acquired by practice with it, I can vouch for by
personal experience. These glass pill-boxes are useful, also, in
admitting of the examination of specimens, so that worthless or common
species can be discarded and only desired forms kept. The method of
holding these boxes is illustrated in the accompanying illustrations.
(Figs. 72, 73.) A drop of chloroform on the bottom of the box at once
stupefies the capture so that it can be taken out and otherwise disposed
of.
[Illustration: FIG. 73.--Same, showing method of closing pill-box after
the specimen is secured (original).]
The necessity of rearing to obtain perfect specimens is even more
important in the case of the Microlepidoptera than with the larger
forms, and many species are very easily reared and can thus be obtained
in quantity. The Micros are abundant from early spring to late fall
about shrubbery, in open fields, and along the edges of woods. They are,
for the most part, day fliers, being on the wing chiefly in the latter
part of the day and early evening. As soon as collected they should be
transferred to pill-boxes and the greatest care should be exercised to
avoid mutilating them, as the slightest touch will denude them of a
portion of their scales or break their limbs or antennae. Lord Walsingham
thus gives his experience in collecting Micros:
I go out with a coat provided with large pockets inside and out,
containing an assortment of pill-boxes, generally of three sizes,
glass-bottomed pill-boxes preferred, a bag slung over my shoulder, and a
net. Unless searching for particular day-flying species, I prefer the
last three hours before dark. As the sun goes down many species move
which do not stir at other times. I watch the tops of the grass, the
stems of the flowers, the twigs of the trees; I disturb leaves and
low-growing plants with a short switch and secure each little moth that
moves, taking each out of the net in a separate pill-box, selected
according to the size of the insect, as he runs up the net to escape.
Transferring the full boxes to the bag I continue the process until
moths cease flying or night sets in. Many species can be taken with a
lamp after dark.
_Collecting the early States._--The careful entomologist who prides
himself on the appearance of his specimens, will, as stated above, rely
largely on collecting the early states and on rearing the insects, for
his material. The Macrolepidoptera have either a single or two broods,
or more, in a season, and the collection of the early states will be
greatly facilitated if a knowledge of the insect's life-habits is first
obtained. The eggs are often found on the food plants of the species,
and where they are deposited in masses they afford a very easy method of
getting the larvae in numbers. In many cases, however, the eggs are
deposited singly and their discovery then becomes a difficult matter.
More satisfactory in some respects is the method of obtaining the eggs
from captured gravid females, and the general collector should always be
on the lookout for females of rare species from which he may be able to
obtain eggs. A single battered female may, in this way, be the source of
large numbers of excellent reared specimens. Many rare Lepidopterous
larvae may be obtained by the use of the beating net and by beating
foliage over an umbrella. A very satisfactory method consists in
collecting pupae, which may frequently be found in numbers about the
bases of the trees on which the larvae feed. Many larvae of the large
family of Owlet Moths (_Noctuidae_) are found either on the surface of
the ground or under various substances, while others burrow into the
stems of the different herbaceous plants, some being subaquatic and
feeding on the underside of leaves or in the stems of aquatic plants. In
the case of Microlepidoptera, their habit as larvae, of mining leaves or
tying or webbing them together, affords an easy means of detecting their
presence in most cases. The miners are easily noticed by the discolored
spots on the leaves or the wavy, pale, or brown lines marking their
burrows. The presence of others is indicated by the leaves being drawn
together and united with webs, or withered and brown from being
skeletonized by the larvae. Many species are case-bearers, and live upon
the leaves and branches of trees and plants, dragging their cases along
with them. Others burrow in grasses or in the stems of plants or the
trunks of trees, or in fungi. In the case of the leaf-miners and
leaf-tiers, little difficulty is experienced in rearing the imagoes.
The care of the larvae, the outfit required, and the methods of breeding
will be described in later sections.