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P art II.
in one season. After many curions details, M. Reaimnu- goes on to describe the appearance
of these insects on the banks of the river, neai- his residence, in August, 1738.
“ The quantity of epheincræ which filled the air can neither be expressed nor conceived.
When snoAV falls thickest, and in the lai-gest flakes, the air is never so completely filled
Avith them, as that which sun-ounded us was Avith cphemeræ. Scarcely had I remained a
fcAV minutes iu one place, when the step on Avhich I stood was covered in every part
Avith tlieir bodies to the depth of tAvo or three, and in some places even to more than four
inches. The Avhole surfiice of the water, for six feet at least fi-om the bank, Avas
entirely covered Avdth a coat of ephemeræ; those Avhich the cunent can-ied off were more
than replaced by those which fell continually in that place. I Avas several times obliged
to abandon my station, by retreating to the top of the stair, not being able to sustain
the shower ofephemeric, Avhich, not falling pei-pendiciilarly, or Avith an obliquity equally
constant, struck me unintei-ruptedly, and iu a very troublesome manner, on all parts
of the face. A t the end of about half an hour from its commencement, the great
shoAver began to abate ; and, in little more than an hour, scarcely any [living] ephemeræ
could be seen.”
1639. The moth-Jiies or case worms {fig. 283. c, Pliryganca rhómbica) arc to be noticed
as beneficial insects, on account of the food Avhich they afford in the laiwæ state to fishes.
Residing in the water, and being of a tender texture, they foi-m moA-eable cases of bits
of sand, sticks, &e., in which they reside. On account of their peculiar characters they
have been sepai-ated from the other Neuróptera by many entomologists, and formed into
a separate order called Trichóptera.
1 6 4 0 . H y m e n ó p t e r a . The wings are fom- in number, transparent, of unequal size, the
fore pair being the largest, and Avith but few reticulations. The mouth is furnished witli
strong juAvs for biting ; the body of the female is armed with a sting or borer ; and the
larvæ (with the exception of those of the saw-flies) are fleshy grubs destitute of legs ;
whilst the pupæ are inactive, resembling those of beetles. Many of the insects in this order
are more intelligent, and more beneficial to man, than any others. The different species
of honey-bees, in all parts of the world, supply him with honey. The ant, particularly
in tropical countries, is the grand promoter of vegetable decomposition ; and the innumerable
hosts of ichneumon flies can-y on a perpetual warfare with various descriptions of
caterpillars that infest vegetation. Some of the species, hoAvevcr, are to be regarded as
obnoxious insects, amongst Avhich are to be especially mentioned many of the species of
saAv-flies (Tenthredinidæ), the caterpillai-s of Avhich are furnished Avith numerous legs
closely resembling those of butterflies and moths, and Avliich, like them, feed upon the
leaves of various species of plants. ^ Amongst these is the black jack, or nigger caterpillar,
being the laiwa of Athàlia centifôliæ, which in certam seasons proves one of the most
obnoxious of our insect enemies, by devouring the leaves o fth e tm-nips which have been
spared by the turnip flea-beetle. These larvæ are very voracious, and shed their skins
several times. When fuU gi-OAvn they descend into the ground, forming an oval cocoon of
agglutinated earth at the depth of several inches, the interior of which they plaster over
with a Avhite shining secretion, and Avithin Avhich most of the individuals remain until
the following season. The larvæ of different species of the genus Lóphynis are also
very injurious in fir plantations and forests, destroying the young leaves, and often
entirely killing the trees. Another species (Selándria Æ'thiops), belonging to the
same family, often commits serious injui-y,by its laiwæ feeding on the leaves o fth e plum
and pear trees. In this state they are remarkable for being covered over with a black
viscid matter, which exudes fi-om the sides of their bodies, and which giA'es them the appearance
of small slugs. I t is the larva of another species (Nematus grossulàriæ) which
so often entirely defoliates our gooseberry trees ; Avhilst îh n th rèd o testudinària lays
its eggs in the bloom of the apple, the young larvæ as soon as hatched eating the core
of the fruit Avhen it is about the size of a Avalnut, and so causing it to fall. Several
species of Lÿda form portable cases of bits of the leaves of roses, aspens, and nut-trees,
which they cut from the tree and roll up with great ingenuity. Cèphus pygmæ'us, in
its larva state, is very destractive to young wheat plants. The species of the family
Siricidæ are also’very destructive, the larvæ burrowing into the solid wood of various
trees, especially o fth e fir and pine tribes. Sometimes, indeed, they appear in such great
numbers in the neighbom-hood of the great German pine forests as to raise alai-m in the
Mnds of the ignorant, these species, especially -Sirex gigas, being among the largest
insects of the order. The species of Cynipidæ may also be considered as injurious, on
account of the gaüs of different kinds which they foi-m upon various kinds of plants,
thereby disfiguring them ; of these the oak apple, and bedeguar or haii-y gall of the dog-
rose, are common examples. The round galls on the shoots of the oak {fig. 290. j ) are
caused by the Cÿnips quércûs fôlii (A). The gall nut of commerce is caused by the
puncture of another species ( Cÿnips gallæ tinctôriæ) upon a species of oak in the Levant ;
and the benefits Avhich have resulted from its use in the manufacture of ink are more
than sufficient to outweigh the injuries committed by the other species in the same
Book IV. ENTOMOLOGY APPLIED TO GARDENS.
family. Many of the species of this order may also be considered as partially obnoxious
on account of the sting Avith which the females are armed ; but most of these sting-
bearing species are serviceable by destroying great numbers of caterpillars, flies, &c.,
which they collect and lay up in their nests as a store of food for their progeny. These
are generally found in the spring and summer months, and are knoAvn by the names of
sand wasps, and solitary wasps ; they are moreover smaller in size than the common Avasp
(Vespa vulgàris), which is one of the most injurious pests in Availed gardens, feeding on
ripe fruit, but also attacking meat, live insects, and, indeed, devouring almost every kind
of article. These should be enticed into phials half filled with sugared Avatcr, or by
treacle spread on a plate or tile, &c. But the most secure plan for their dcstmction is,
to burn sulphur by night at the mouth of their nests, or to pour spirits of tm-pentine on
a piece of cotton wool, which must then be thi-ust into their nests, the mouth in both
cases being covered over with a sod.
1641. L e p i d ó p t e r a . This well-knoAvn and beautiful order is characterised by four
Avings, thin, membranaceous, and covered with a fine poAvdery substance ; this, on being
magnified, is shoAvn to consist of innumerable minute scales, lying one upon another
like those on fishes. Theii- mouth consists of a long and slender spiral proboscis or tongue,
with two poiTected palpi ; and they undergo the changes of caterpillar, chrysalis, and
perfect insect. Lepidopterous insects arc knoAvn in common language by the names of
butterfly, hawk moth, and moth, of each of Avhich there are many thousands of species.
Few lepidopterous insects ai-e injui-ious to the agi-iculturist ; but a gi-cat number devour,
in their caterpillar state, the leaves of trees in the garden, the orchard, and the plantation.
A few of these will be noticed under the particulai- tribes to Avhich they belong.
1642. Butterflies (Jdapiliónidce). The insects of this numerous and splendid tribe are
well characterised by flying only dm-ing the day, and by their antenna terminating in
a small knob. In their caterpillar state, they all feed upon the leaves of plants ; and
Avhen they change into chrysalides, either suspend themselves by the tail in some retired
situation, or attach themselves to some object by means of an additional strong transverse
thread ; but they never spin a cocoon, or undergo their metamoi-phosis in the ground.
Many species of tliis beautiful tribe are found in Britain, and several of the finest may
be easily reared by feeding their caterpillars in cages Avith the leaves of the plant on Avliicli
they subsist. To assist tliose who are disposed to try this interesting experiment, wc
subjoin a description of the different caterpillars from which they are produced, and
which may be frequently met with, by seai-ching for them, at the proper season, upon
the plants they eat.
1643. Caterpillars not injurious to cultivated vegetables, but Avhich may be introduced
in gardens, ai-e of the following buttei-flies :— 1. Swallow-tail butterfly (Papilio Machàow)
{fig. 284.). The caterpillar is green, but each segment of the body has a black transvei
se band, relieved by small, round, reddish sp o ts: its natural food is umbeUiferous
plants, particulai-ly the fennel and the can-ot; when full-fed it is about two inches long
and chano-es into a greenish chrysalis ; and there ai-e two broods in the year. This is the
most beautiful, and one of the rarer British species.— 2. The Brimstone YelloAv buttei-fly.
The caterpillar is of a pale green, with a whitish stripe on each side, and a reddish broAvn
h e a d ; and w h en full fed, it measures one inch and a half in length : it feeds on the buckthorn
and wild rose. There are also tAvo broods in the year of this species. — 3. The
Orange-tip butterfly. The caterpillar of this species is entirely of a pale green colour,
very much resembling that of the turnip buttei-fly, but without the small eye-like spots
K K 2