only during the twilight, whether in the morning or evening; but the
term may be understood, with some latitude, to signify all those
insects that are seen only in the morning and evening, though after
sunrise and before sunset. Of these, some come forth only in the
_morning_, others only in the _evening_, and others both _morning_
and _evening_. My memory only furnishes me with a single instance of
an insect whose principal appearance and flight are in the _morning_.
_Catocala nupta_ I have often seen flying at this time, about six or
seven o'clock, and never at any other: I am not however prepared to
assert that it does not appear in the evening or night, but I have
then never met with it. In the _evening_ more particularly you hear
the hum of the dung-beetle (_Geotrupes_), which Linné thought the
prognostic of a following fine day; and of the swarms of _Melolontha
vulgaris_ and _Amphimalla solstitialis_. Then also many other
_Coleoptera_ are in the air; especially before a thunderstorm, a
state of the atmosphere that particularly excites insects[1552]:
_Ptinus imperialis_ and _germanus_ I have never taken except under
these circumstances. Then the _Ephemeræ_ sport in the air, and lead
their mystic dance. The majority of the hawkmoths are then too on
the wing, with their long tongues imbibing the nectar of the flowers
while they hover over them, both _morning_ and _evening_.
iii. In the _night_ the main body of the _moths_ take their flight, as
well as a vast number of _Coleoptera_ and insects of other orders. At
this time the _Blattæ_ and crickets leave their hiding-places and run
about: but the other _Grylli_ L., though they sing in the night, fly
only in the day. Then also the _Carabi_, like beasts of prey, leave
their dark retreats,--in this differing from the _Cicindelæ_, which
are diurnal,--and prowl about to entrap other unwary insects. Then,
likewise, the female glowworm hangs out her lamp of love, and the male,
led by it, wings his way to her: and then the water-beetles (_Dytisci_,
_Gyrini_, &c.) forsake the waves and become tenants of the air.
Could we with certainty discover the stations in which insects after
their excursions take their _repose_, we might capture many that
we now search for in vain. Several of these stations were pointed
out in a former part of this letter where I detailed their usual
_haunts_. I may here add, that numbers of them, when reposing,
conceal themselves from their enemies on the under side of the
leaves of trees and plants. Moths, especially the _Noctuidæ_, may
often be met with in woods, as before observed[1553], on the _north_
side of the trunks of trees. Mr. Marsham related to me, that once a
little before sunset, observing over his head a number of insects
on the wing moving on in one direction, he caught some of them, and
they proved to be _Labia minor_. Struck with the circumstance, he
watched them several evenings; and on one, as he was looking about
a melon-pit for insects, he saw these little animals alight on the
frame, hastily fold up their wings, and entering under the glasses,
run down its sides and bury themselves in the loose earth. This he
observed repeatedly. The onward flight of these insects was therefore
evidently their return from their diurnal cruise to their nocturnal
station.--This happened in September.
I am, &c.
FOOTNOTES:
[1458] Linn. _Philos. Botan._ § 334.
[1459] _Linn. Trans._ x. 20--. &c. _Dict. des Scienc. Nat._ xviii.
[1460] _Selborne_ i. 173.
[1461] _Philos. Entomolog._ ix. § 20.
[1462] _Mém. du Mus._ 1815.
[1463] _Hor. Entomolog._ 42--. 518.
[1464] _Essai Elément. de Géograph. Botan._ 62.
[1465] _Wisdom of God_, &c. 2d edit. 9.
[1466] _Hor. Entomolog._ 469. This calculation includes the _Crustacea_.
[1467] It has lately been discovered that the larva of _Drilus
flavescens_, a beetle, feeds upon the common snail. (_Bulletin des
Scienc. Nat._ 1824. iii. 297; v. 110; vi. 221.) I have found an
_Acarus_ on the same animal.
[1468] See above, p. 219--.
[1469] We employ this term, because the more common one, _herbivorous_,
does not properly include devourers of timber, fungi, &c.
[1470] If we consider the number of species of _Acari_, _Nirmi_,
_Poduræ_, and _Araneidæ_, this proportion will appear moderate.
[1471] _Hor. Entomolog._ 48.
[1472] _Philos. Entomolog._ ix. § 20.
[1473] _Géograph. Génér. des Ins._ 5.
[1474] _Ibid._
[1475] _Ibid._ 7--.
[1476] _Ibid._ 8, 11.
[1477] _Personal Narrat._ E. T. v. 88. He says also that each stream
almost has its peculiar species (_Ibid._ 98), and that they sometimes
emigrate to stations they had not infested before. _Ibid._ 106--.
[1478] _Hor. Entomolog._ 519.
[1479] Latr. _ubi supr._ 3.
[1480] _Géographie_, &c. 22--.
[1481] _Ibid._ 27.
[1482] _Géographie_, &c. 20--.
[1483] See above, p. 494.
[1484] As this insect is the type of a distinct genus amongst the
_Scutelleridæ_, I have distinguished it by the name Fabricius gave
the whole tribe.
[1485] M. Latreille (_Géographie_, &c. 8.) seems to regard
these varieties as _distinct_; in which case they would be the
_representatives_ of the species named in the text: but the
variations are mostly so slight, as not to afford any satisfactory
distinctive characters.
[1486] _Géogr. Génér. des Ins._ 2.
[1487] When I described the Melville Island insects for Captain
Sabine, I received from him no _Culices_; but I afterwards saw in his
possession a genuine one from thence.--K.
[1488] _Linn. Trans._ xii. 380--. n. 6, 7.
[1489] _Ibid._ n. 5.
[1490] Dejean in his catalogue gives only 434 species; while Mr.
Stephens, _four_ years ago, had 550, and has since increased the
number to above 600.
[1491] _Journal of a Tour in Iceland_, 272.
[1492] VOL. I. p. 115--.
[1493] _Entomogr. Russ._ Coleopt. _t._ xiii. _f._ 1.
[1494] Ahren's _Fn. Europ._ i. 1.
[1495] _Hor. Ent._ 47--.
[1496] _Annulosa Javanica_, 36.
[1497] See the Rev. L. Guilding's admirable _History_ of _Xylocopa
Teredo_ and _Horia_ (_Cissites_ Latr.) _maculata_, Linn. Trans, xiv.
313--.
[1498] Out of 51 species described by Bilberg, 28 are African, and 19
of these are from the Cape.
[1499] _Géogr. Génér. des Ins._ 18.
[1500] _Hor. Entomolog._ 45.
[1501] Dr. Leach has described 8 British species (_Linn. Trans._ xi.
37.); Dejean has 7 Spanish ones.
[1502] I have a very splendid species of this genus taken by C. C.
Elwes Esq. on the Pyrenees, which is undescribed, and falls under
none of the count Dejean's Families, having its elytra perfectly
smooth, without striæ, punctures, &c. It is of a brilliant golden
green. It stands in my cabinet under the name of _C. lævigatus_. K.
[1503] Fischer _Entomogr. Russ._ 90--. _t._ viii. _f._ 13.
[1504] VOL. III. p. 562.
[1505] Major General Hardwicke gave me one of this description from
Nepal.
[1506] Latr. _Géograph._ &c. 18--.
[1507] _Linn. Trans._ xiv. _t._ iii. _f._ 4.
[1508] _Hor. Entom._ 147.
[1509] _Linn. Trans._ ubi supr. _f._ 1.
[1510] _Ibid._ xii. _t._ xxi. _f._ 9.
[1511] _Ibid._ _f._ 14.
[1512] To this genus belong _Melolontha aurulenta_. Ibid. 400; and
_M. sericea_. Ibid. 463.
[1513] Latr. _Géograph._ 7.
[1514] _Cetonia atropunctata_ and _Brownii_ of _Linn. Trans._ (xii.
464. _t._ xxiii. _f._ 6.) belong to this genus.
[1515] _Linn. Trans._ xii. _t._ xxii. _f._ 2; _t._ xxiii. _f._ 7.
[1516] Latreille, _Géograph._ &c. 10.
[1517] _Linn. Trans._ xiv. 569.
[1518] See above, p. 496.
[1519] Fischer, _Entomogr. Russ._ i. 135.
[1520] From finding it in water, Fabricius considered this insect as
a _Hydrophilus_, but it is a true _Cercyon_.
[1521] See above, p. 401.
[1522] _Personal Narrat._ E. T. v. 91--.
[1523] See VOL. I. p. 470--.
[1524] A species of _Gyrinus_ (_G. Viola aquatica_), described by
Modeer (_Linn. Syst. Nat._ Ed. Gmel. i. 1612. n. 9.), is said to
inhabit _salt_ water.
[1525] _Géograph._ &c. 6.
[1526] _Apis_ *., a. _Mon. Ap. Angl._ ii. 178--.
[1527] _Linn. Trans._ iv. 30--. v. 96--. _t._ iv.
[1528] VOL. I. LETTER VI.
[1529] _Géograph._ &c. 6.
[1530] VOL. II. p. 255.
[1531] These, as well as _Melecta_, are probably a kind of
_Cuckow_-bee. _Mon. Ap. Angl._ i. 150.
[1532] _Melitta_ * *. b. _Mon. Ap. Angl._ i. 138--.
[1533] _Mémoires sur le gènre_ Halicte.
[1534] VOL. II. p. 9.
[1535] _Linn. Trans._ ix. 78--. _t._ i. _f._ 20.
[1536] _Ibid._ 55. _t._ i. _f._ 12.
[1537] This insect does not, I believe, eat the petals of the rose,
but _laps_ the nectar it produces. I have seen it employed upon
wounded trees lapping the sap.
[1538] _Mon. Ap. Angl._ ii. 172. 257.
[1539] See above, p. 491, note^a.
[1540] _Ibid._ p. 219; and VOL. I. p. 267--.
[1541] _Ibid._ p. 256--.
[1542] _Apis_ * *. e. 2. K.
[1543] _Apis_ * *. c. 2. α. K.
[1544] _Butterfly Collector's Vade Mecum_, 66, note^d.
[1545] De Geer ii. 638--. 641--.
[1546] Swamm. _Bibl. Nat._ i. Conf. 114 with 103.
[1547] Reaum. vi. 480--.
[1548] VOL. II. p. 11.
[1549] _Lepidopt. Britann._ 263--.
[1550] _Linn. Trans._ v. 256.
[1551] VOL. II. p. 95--.
[1552] See above, p. 254--.
[1553] VOL. II. p. 217. See above, p. 200.
LETTER L.
_ON ENTOMOLOGICAL INSTRUMENTS; AND
THE BEST METHODS OF COLLECTING,
BREEDING, AND PRESERVING INSECTS._
Having in my last letter given you some account of the _haunts_ of
insects, I now proceed to describe the various _instruments_ with
which you ought to be provided, to enable you to collect them; and
the best mode of employing each. The Entomologist when he makes an
excursion should have _three_ principal objects in view, for which
he ought to be duly prepared. The first is to _find_ insects, the
next is to _catch_ them, and the last when taken to bring them _safe_
home. In exploring their haunts he must also recollect that some
will be _reposing_; others _feeding_; others _walking_ or _running_;
others _flying_; others _swimming_; others _lurking_ in various
places of concealment, and in _different_ states of existence; and
that he must be prepared with means of coming at and capturing them
under all these circumstances.
1. First furnish yourself with a strong _knife_ or other instrument
with which you can raise the bark or penetrate the wood of any
tree, when circumstances indicate that insects are busy below the
one or within the other. There is no better tool for this and
other purposes than Mr. Samouelle's _digger_, which consists of an
iron five inches long, rather more than one-third of an inch in
diameter, forming a curve towards the extremity, terminating in a
lozenge-shaped point, and strongly fixed in a wooden handle[1554].
With this you may not only explore the interior of timber-trees, but
grub up the turf under them, and examine the earth for the pupæ of
_Lepidoptera_. When your object is merely this _latter_ purpose, a
potato-fork--which is better than a spade, as it will seldom injure
the pupæ--will be your best implement.
2. Next have a _stick_, to resemble a common walking-stick,
sufficiently stout to beat the branches of the trees and shrubs, fitted
at one end with a male screw, and at the other with a female, with a
brass cap to screw over each to keep the dirt from them. Besides this,
you may carry with you a spare piece or two about a foot long, properly
equipped to screw to it when you want to lengthen it.
3. Another implement must be a _bag-net_[1555]. This consists of a
hoop of stout brass wire about nine inches or a foot in diameter,
with a socket to receive the end of your stick, or, what is more
secure, a screw to fix it to it, with a bag of gauze, muslin, or
fine canvass, about twelve inches deep, sewed round it. The French
collectors use a net of this kind, in which the hoop is formed of
two semicircular pieces of iron or brass wire hooked together at
one end, and at the other made to lap over the corresponding piece,
and pierced to receive the screw at one end of your stick. When
not employed, they double the hoop and conceal it under the vest;
they fix to it a muslin bag of two feet long. This net is made to
serve various purposes. With it they catch _Lepidoptera_ and other
_flying_ insects; and an adroit collector by giving it a certain
twist completely closes the mouth, so as to prevent the escape of
his captives. Fixed to a very long pole (Mr. Haworth says it should
be _twenty_ or _thirty_ feet long[1556]), it is the best net for
the purple emperor butterfly (_Apatura Iris_). It is also used with
success to _push_ before you through the _grass_ of meadows, woods,
&c., and thus often displaces numerous insects, which fall into
it;--every now and then it is examined, and the valuable captures
secured. The common bag-net will perform the same operations, but
is not deep enough for _flying_ insects. If you lengthen your stick
before you screw it on, it enables you to brush with it the weeds
at the sides and bottom of ditches. This employment of brushing the
grass, &c. may be carried on if you are walking with any friend not
interested in Entomology, without much interruption of conversation.
For this last operation--sweeping the grass, &c.--if you wish at any
time to devote a morning wholly to it, you will find a net invented
by the late Mr. Paul, of Starston in Norfolk, and which he employs
to clear his turnips of _Haltica Nemorum_[1557], a very useful
implement. The accompanying figure will give you a better idea of it
than any description[1558]; you may make it large or small according
to your convenience: the wider it is, the greater space it will brush
at once. When your object is a more general investigation, the
bag-net just described is preferable.
4. Scarcely any implement seems a greater favourite with British
collectors than what may be called the _fly-net_[1559]. This is
universally employed by them for capturing _flying_ insects,
especially _Lepidoptera_. It is similar to what is called a
_bat-fowling_ net, and should be made of green or white gauze or
coarse muslin. The _former_ colour, as being less visible, is most
proper for _mothing_ in the _night_; but the _latter_ is best for the
_day_, as this net is useful to hold under the branches of trees and
shrubs to receive the insects that fall when they are beaten. The
rods for the net we are considering,--which should be about five feet
long, half an inch in diameter at the base, and gradually tapering
to the end,--must be made of some tough wood; each should consist of
about four joints for the convenience of carriage, and each joint
should be fitted with a socket at the lower extremity, to receive the
top of the joint below it: the terminal joint must either be bent
into a curve, or fitted with an angular socket or ferrule, so as to
form an obtuse angle with the rest of the rod[1560]. The gauze which
is to form the net, being cut into the requisite shape, should be
welted round, except at the bottom, where it should have a deep fold
or a bag for preventing the escape of the included insects--in order
to form a slide for the rods to slip in. At the apex where they meet,
a few stitches should be set, or a piece of leather sewed in, to
prevent their going too far. At the bottom, on each side, two strings
must be sewed on the net, to receive which there must be a hole in
each rod about six inches from the bottom: these must be tied, which
will keep the net from slipping upwards. When you go after moths
and other insects that fly in the _night_, a plan, as I am told,
of some of the London collectors may be adopted with advantage.
Cause a lanthorn to be made with a concave back, and furnished with
a reflector: this must be fastened, by means of a strap, upon the
stomach. If you hold your expanded fly-net before this (as nocturnal
insects fly to the light), you may thus entrap a considerable number.
In sultry summer nights also, if you place a candle on a table in a
summer-house, or even in a common apartment, and open the windows,
you will often have excellent sport, and take insects you might
otherwise never meet with.
When you use your fly-net, you must take the rods one in each hand,
so as to keep it extended; and when you have brought it fairly beyond
the insect you are pursuing,--to accomplish which you must be upon
the alert,--you must bring the two sticks together, which, if you
are commonly dexterous, will capture your prey. This net is likewise
useful in taking winged insects when at rest upon the ground, by
simply spreading it over them. When you use it to beat into, as above
recommended, you must take both the sticks in one hand, and extend it
by crossing them as much as you can. In the absence of this, a common
umbrella, or even a sheet of stiff paper which you may carry folded
in your pocket, are no bad substitutes. When your object is _beating
the bushes_, bring your fly-net, &c. rapidly under the branches you
mean to operate upon, or the insects will fall from them to the
ground before you are prepared.
Under this head I may mention a very ingenious net for taking
_Lepidoptera_, particularly _butterflies_, invented by Dr. Maclean
of Colchester, which I would call _Maclean's elastic net_. It is
constructed of two pieces of stout, split cane, connected by a joint
at each end and with a rod which lies between them, in which a pulley
is fixed; through this a cord fastened to the canes passes; a long
cane with a ferrule receives the lower end of the rod and forms a
handle; and to the canes is fastened a net of green gauze. Taking the
handle in your right hand, and the string in your left, when you pull
the latter the canes bend till they form a hoop, and the net appended
to them is open; when your prey is in it, relax the cord, and the
canes become straight and close the mouth of the net, keeping them
close with your left hand, you may soon disable your prey with your
right. Dr. Maclean has scarcely ever found this net fail.
5. Another instrument which should be constantly in the hands of the
Entomologist is the _forceps_[1561]. This is particularly useful
for catching _Diptera_ and _Hymenoptera_ chiefly while at rest on
the leaves and flowers of plants. Both these tribes are usually too
agile to be taken by the hand alone, which besides without this
contrivance would be exposed to the stings of many of the latter.
The leaves of the forceps should be _octagonal_, five or six inches
in diameter, and covered with green gauze, or rather very fine
catgut, which will enable the head of a lace-pin to pass through
it. You must direct your artisan to make the joint of the handle
nearer the rings for the finger and thumb than to the leaves, or the
instrument will not open well. An old pair of curling-irons might
be made into very good handles; but the hoop to which the catgut
is fastened should be brass, or if iron it ought to be painted to
secure it from rust. Some make the leaves of the forceps _round_;
but when an insect is perched on a wall or any _vertical_ surface,
it has less chance of escape if you can apply a straight side to its
station. The Germans use a much longer and larger instrument of this
kind, having leaves of ten or twelve inches in diameter, which they
use to catch _Lepidoptera_ when settled on plants. When you aim at
an insect with your forceps, you must expand the leaves as much as
possible, and cautiously approach your prey; and when within reach,
close them upon it suddenly, including the leaf or flower on which
it rests. As these are sometimes bulky, and prevent the instrument
from shutting closely,--that the included insect may not escape, it
is often necessary to use the other hand to bring them together, when
the pressure of the finger and thumb soon disables it.
6. As the _waters_, whether running or stagnant, as well as the earth
and the air, teem with insects, you must likewise be provided with
a net of a different description from any of the preceding, that
you may _fish_ them out. It may be made of fine canvass, just deep
enough to prevent the insect from jumping out, and fastened to a
brass hoop five or six inches in diameter, not perfectly circular,
but having the segment of a circle cut off anteriorly, so that it
will apply well to a flat vertical surface; and fitted posteriorly
with a socket, to receive the end of your stick; or, what is better,
with a _screw_, which will securely fasten it to it[1562]. In using
this net, different modes may be adopted. You may either watch
the motions of an individual insect, and secure it by darting the
net beyond it and drawing it towards you; or by placing it quietly
under it, and then elevating it suddenly; or you may push your net
at random along the margins of the pools and rivers amongst the
weeds, &c.; amongst the duck-weed (_Lemna_) on their surface, or
the mud at the bottom; and when you examine its contents, you will
often find valuable captures. I have thus sometimes got rich booty
in the most unlikely places;--such as _Hydræna longipalpis_, and an
allied nondescript species, &c.; and by fishing amongst _Zanichellia
palustris_, _Hæmonia Zosteræ_. If at any time you do not happen to
have your water-net with you, with a common rake you may take the
duck-weed from the surface of a pool, and upon examination you will
often detect amongst it many minute water-beetles.
But besides all these implements you will find your _finger_ and
_thumb_ a very _handy_ forceps when insects are stationary or walking
upon the ground; and even when flying, minute ones that you would not
otherwise meet with may be taken by the palm of your hand, wetted
with saliva, if, when you see them swarming in the air, you pass
it to and fro amongst them. When such are stationary, or moving on
the ground, on rails, the trunks of trees, &c., the fore-finger,
so wetted, will often best secure them: but if they are perched on
a summit or a vertical surface, before you approach near enough
to alarm them bring forward quietly your bag-net, and hold it so
that they may fall into it, if they attempt by falling to escape
you. Other methods of entrapping insects may also be pursued with
success. A table-cloth spread on the grass in the open parts of
a wood I have known allure several scarce insects: a lady's white
dress is equally attractive. An old mattress, laid at night upon a
grass-plat, if suddenly reversed in the morning, will supply the
Entomologist occasionally with good _Coleoptera_. No better trap for
the _Silphidæ_, _Dermestidæ_, &c., than a piece of carrion, a frog,
or mole, &c. The numerous insects that inhabit excrement of every
kind, especially that of the cow and the horse, may be best taken by
immersing their pabulum in water: for this purpose, let a boy carry
a spade and pail to the scene of action, and filling the pail nearly
full of water begin the operation, and all the insects lurking in the
submerged dung will come to the surface, and may be easily taken.