ENTOMOLOGY.-NO. 2 . 
373 
they change into chrysalides, either suspend them¬ 
selves by the tail in some retired situation, or 
attach themselves to some object by means of a 
strong transverse thread; but they never spin a 
cocoon, nor undergo their metamorphoses in the 
ground. 
The hawk-moths form the second division of 
lepidopterous insects, and are only to be seen on 
the wing at the rising and setting of the sun, that 
is, in the former and latter part of the day. Their 
flight is so extremely rapid, that the eye cannot dis¬ 
tinguish the motion of their wings, nor the colors 
which ornament them. The caterpillars of the 
larger kinds are, in general, very beautiful; and 
are easily known from those of butterflies, and of 
other moths, by a sort of horn or curved process, 
issuing from the last segment of the body. None 
of these are found to be injurious to the gardener 
or farmer, and only three or four kinds of the 
butterfly, while the moths, the third grand division 
of lepidopterous insects, are not only the most nu¬ 
merous, but among them we find the greatest pro¬ 
portion of injurious and destructive species. Nearly 
all, in their caterpillar state, are external feeders, 
that is, they feed upon leaves. On changing into 
the chrysalis state, they either conceal themselves 
in a silken cocoon, or burrow in the earth, but are 
never exposed like butterflies. The perfect insect 
seeks its food during the night, generally beginning 
their flight in the dusk of the evening. Fruit trees, 
but more particularly apple trees, are subject to the 
attacks of many lepidopterous caterpillars. Inde¬ 
pendently of the various causes of blight, proceed¬ 
ing from the soil and the weather, there are others 
entirely originating in insects. Orchardists fre¬ 
quently find the tender leaves on the young apple 
shoots have the appearance of being sown or woven 
together, or rolled up and withered ; now it is 
beyond all doubt that neither heat, cold, nor fungi, 
have the least agency in causing these injuries; 
they are, in fact, entirely produced by two small 
caterpillars of two different species of small moth, 
and if the leaves are separated and carefully un¬ 
rolled, these depredators will be detected. From 
the lamentable neglect that agricultural entomology 
has hitherto received, the perfect insects have never 
been ascertained, and even the effects which they 
produce have been attributed to other causes. 
The larva of the ghost-moth attacks and does 
much mischief to the roots of the hop-plant. The 
giant goat-moth, as a caterpillar, lives entirely 
within the trunk of the willow, and soon brings it 
to decay. A small moth eats the culm of the rye 
within the vagina, and thus destroys many ears; 
while our woollen garments, furs, feathers, and 
even books, are sometimes ruined by the depreda¬ 
tions of three or four other little moths, unfortu¬ 
nately too well-known in our dwellings. 
Hymenoptera .—Insects of this order have four 
transparent wings, and the tarsus, forming the 
third or outer division of the foot, is composed of 
five joints, while the body is armed with a sting. 
The insects of this order are more intelligent and 
more beneficial to man than any others. The nu¬ 
merous species of bees supply him with honey; 
the ant (particularly in tropical climates) is a grand 
promoter of vegetable decomposition; and the in¬ 
numerable host of ichneumon flies carry on a per¬ 
petual warfare with every description of cater¬ 
pillar. The large autumnal wasp is the only inju¬ 
rious hymenopterous insect in gardens, the small 
early wasp being in a measure beneficial. 
Hemiptera .—The chief characteristic of this 
order, is that the mouth is in the form of a slendet 
and lengthened proboscis, which, when not used, 
is folded beneath the breast, but not coiled up, as ir. 
lepidopterous insects. The wings are four, two oi 
which are always clear, and the others generally 
semi-transparent. One division of this order feed 
upon insects, and consequently are not injurious to 
gardens, but the other division feed upon vegetable 
juices, as plant-lice, plant-bugs, &c. 
The aphides or plant-lice, next to locusts, are 
the most universal devastators of vegetables. 
Almost every plant is attacked by them ; and their 
fecundity is so prodigious, that Reaumur has proved 
that, in five generations, one aphis may be the pro¬ 
genitor of 5,904,900,000 descendants; and it is 
supposed that, in one year, there may be ten gene¬ 
rations. The injury they cause is produced by 
sucking or pumping out the juices of the shoots. A 
portion of them only are provided with wings, 
which, as has been before observed, are four in 
number. Some species are not so prolific as 
others; but those feeding upon the different kinds 
of pulse, and on flowering plants in general, in¬ 
crease so rapidly and take such entire possession 
of whatever they fix upon, that vegetation is 
checked, and often destroyed. The aphis meets 
with a powerful enemy in the lady-bird or lady- 
bug ; for it has been often observed that when vast 
numbers of these interesting little beetles are seen, 
it is where the aphides have been very plenty. Mr. 
Kirby, an English writer, states, that in 1807, the 
shore at Brighton, and on the south coast, was 
literally covered with these little beetles, to the 
great surprise and even alarm of the inhabitants, 
who were ignorant that their little visitors w r ere 
emigrants from the neighboring hop-grounds, 
where, in their larva state, each had slain his thou¬ 
sands and tens of thousands of the aphis, known to 
the hop-growers under the name of the fly. 
Coleoptera .—This extensive and well-defined 
order comprehends all those insects generally called 
beetles. They have four wings, but two of them 
assume the form of hard wing-cases, which meet 
close together in a straight line down the back. 
There are many tribes of these insects, which, both 
in their larva and perfect state, are extensively in¬ 
jurious to the gardener and agriculturist. The 
May-bug is one of the most destructive insects in 
this country. The female deposits her eggs in the 
ground, where, in a short time, they change into 
young grubs; these, when full fed. are about one 
and a half inches long, soft and white, with a red¬ 
dish head and strong jaws. These grubs are 
known to farmers as the potato-worm, from their 
ravages upon the tubers of this vegetable. In this 
state the insect remains four years, at the end of 
which it digs in the earth three or four feet deeper, 
and spins itself a smooth case, where it changes to 
the chrysalis, and the following spring comes forth 
in its perfect form. Various species of weevil, 
most of them very small, do considerable injury; 
as all the species live, in their larva and pupa 
state, upon seeds and vegetables. 
