^ •
,lL
1622. AU insects are divided into two primary groups, which are either winged or
apterous (not winged). 1. Winged insects (Ptiiota Aristotle) undergo the changes we
have already described ; they are first larvæ, then pupæ, and finally become provided
Avith four or two wings capable of flight. These are called perfect insects, and comprise
ali buttci-flics, bees, Avasps, beetles, dragon-flies, flies, &c. Ants, likewise, enter into this
great division ; for although the majority of those Avliich Ave see are Avitliout Avings, still
they arc only the neuters or imperfect ants, the tme males and females being each
furnished Avith four wings. 2. Apterous insects, on the other hand, are those which in no
period of their existence are ever furnished witii wings ; as the spider, centipede, crab,
louse, &c. They undergo little or no metamorphosis ; that is, they come from the egg
nearly in the same form Avhich they ai-e destined always to preserve.
1623. Three principal modes o f arrangement of the insect tribes have been adopted by
naturalists. SAvammcrdam took the valuations of the metamorphoses of insects as the
grounds of his classification ; Linnæus regarded the differences in the structure and number
of the wings as of primary importance; Avliilst Fabricius considered the modifications
of form in the pai-ts of the mouth (indicating, of course, corresponding differences in the
mode of feeding, and natm-e of the food of the difi'erent tribes,) as affording the most
natui-al chai-acters for the distribution of these animals. These different modes of classification
ai-e named the metamorphotic, alai-y, and cibarian systems; and their modifications
or combinations foi-m the groundAvork of the aiTangements of all subsequent authors.
1624. Entomologists are not yet agreed in adopting an unii'orm system of arrangement,
although the classification of Latreille (which, from combining the most important
characters of each of the thi-ee systems of Swammerdam, Linnæus, and Fabricius, has
received the name of the eclectic system) has, perhaps, been more universally adopted than
any of the other attempts recently made towards a natural classification of insects.
1625. Without entering into any detail, in a AVork like the present, as to the pcculiai-
chaïoætcrs which have led to the establishment of separate orders for the liea, eai-wig,
Thi-ips, Stylops, and caddice-flies ; it will be suflicient for all practical purposes to state
that, Avith these exceptions, all those articulated animals which undergo a system o f metamorphosis
whereby (in the majority of cases) wings are developed, are dÍA-isible into two
gi-eat groups, namely, those which take their food by means of jaws for mastication, and
those Avhicli ai-e provided with a suctorial apparatus for pumping up fluid matter for
their subsistence. The former primary gi-oup (Mandibulata, or insects provided with
mandibles or jaws) is divided into the orders, 1. Coleóptera; 2. Orthóptera (including
the Euplexóptera and Thysanóptera) ; 3. Ncuróptcra (including the Ti-ichóptcra) ; aud
4. Hyracnóptera. The latter primary group (Haustellata, or insects furnished with a
haustellum or sucker) forms the orders, 5. Lepidóptcra ; 6. Hemiptera ; and 7. Díptera
(with Aphaniptera aud Strepsiptera). The ai-ticulated animals, fui-nished Avith jointed
legs, Avhich do not undergo any metamorphosis whereby wings are developed (A'ptera),
now constitute several distinct classes; namely, 1. Crustácea, generally ten-footed, including
crabs, lobsters, shrimps, &c. ; 2. Arachnida, generally eight-footed, including spiders,
scorpions, mites, &c. ; 3. Myriápoda, many-footed, including centipedes, millepedes, &c. ;
4. Hexápoda, six-footed, including the spring-tailed insects and lice.
1626. Coleóptera. This extensive and Avell-defined order comprehends all those
insects generally called beetles. They have four wings, but two of them assume the
form of hard wing-cases, Avhich meet close together in a straight line doAvn the back.
There are many tribes of these insects, which, both in their larva and perfect state, ai-e
extensively injurious both to the gardener and the agriculturist. The principal of those
Avhich are indigenous to Britain wc shall here enumerate.
1627. The cockchafer (Jfelolontha vulgai-is F., fig. 280. a, b) is one of the most destructive
insects in this country.
280 R is provincially called broAvn
tree-beetle, bhnd-beetle, chafer,
Ja ck homer, Jeifry cock, May-
bug, broAvn clock, dor, and
miller. This insect appears
some years in prodigious numhers,
committing, both as a
gmb or lai-va and in its perfect
state, the greatest ravages. The
female (a ) deposits her eggs
in the ground, Avhere in a short
time they change into young
grubs : these, when full fed,
are about an inch aud a half
long (b) ; they are soft and white, with a reddish head and strong jaws. In this
state the insect remains four years, during Avhich time it commits dreadftil ravages on
the roots of grass, plants, and oven young trees ; gnaAving away the fibres aud bark,
and dcvom-ing the roots, especially in old pastures, so that the tu rf becomes broAvn, and
may be rolled up nearly with as much ease as if it had been cut artificially ; Avhen the
grubs Avill be found beneath it, lying on their sides witliin the mould ; and vast numbers
may be thus gathered, and given to poultry and swine. Wlien full groAvn, the lai-væ
dig in the earth four or five feet deeper, spin a smooth case, and then change into the
chrysalis state {fig. 279. a). In this inactive form they remain until the following spring ;
tlic perfect beetle {fig. 280. a) then comes ft-om the ground, and commences an immediate
attack upon the leaves of all trees, hut more paiticularly on those of the oak.
The following account of the ravages of this insect is so very extraordinary, that, were
it not Avell authenticated by contemporary writers, it Avould appear incredible. In 1688,
the cockchafers appeared on the hedges and trees in the county of Gahvay, in clusters
of thousands, clinging to each other’s backs in the manner of bees Avhen they SAvai-m.
During the day they remained quiet, but toAvards sunset the whole were in motion ; and
the humming noise of then- wings sounded hke distant drums. They were in such prodigious
multitudes, that they darkened the ah- for the space of nearly tlu-ee miles ; and
the noise they made in devouring the leaves Avas so loud, as to have been compared to
the distant saAving of timber. In a short time the leaves of all the trees, for some miles,
were destroyed, leaving the whole country, in the middle of summer, as naked and desolate
as it would have been in Avintcr. Swine and poultry devoured them in vast numbers ;
they waited under the trees for the clusters dropping, aud soon became fat upon this
novel food : even the loAver orders of the people, from these insects having eaten up the
produce of the earth, adopted a mode of cooking them, and also used them as food.
Towards the end of summer, they are said to have suddenly disappeared. {Phil. Trans.,
1697, vol. xix. p. 743, &c.) From subsequent facts, there is reason to believe that these
insects occasionally migi-ate into this country from some part of the Continent, probably
Normandy or Britany ; as, about 1802, all along the south-west coast of Galway, there
A\-ere found dead on the shore, for miles together, such infinite multitudes of cockchafers,
and in such vast heaps, that, by a moderate estimate, it Avas computed there could
not be less than forty or fifty horse-loads in all. These were doubtless a ncAV colony,
intercepted by a storm in their flight to the same districts as had been ravaged by their
ancestors ; but which, meeting Avith a contrary wind, had been driven into the sea, and
destroyed. {Shaw’s Gen. Zool.)
1628. Various species o f weevils (Curcùlio L .), most of them very small, do considerable
injury ; as all the species live, in theii- larva and pupa state, upon seeds and vegetables.
The Balaninus nùcum, or nut Aveevil {fig. 280. ee), is the insect produced by the grub (c, d)
residing in the hazel nut. The female insect singles out a nut, which she pierces with
her proboscis ; and then, turning round, deposits an egg in the cavity : the nut, not
apparently injured, continues to grow, and gradually ripens the kernel upon Avhich the
larva {d) feeds. The perfect insect (e) is of a broAvn. colour, and measures near half an
inch in length, including its slender rostrum. Two species of very small weevils (A'pion
flavifemoràtum and A. flavipes K .) devour the seeds of the purple and white clover.
The corn weevil {Calandra granària F.) is well known from its destmctiveness to wheat ;
and there is also another species equally miscliievous to that grain. Rhynchæ'uus
lâpathi L . devours the Avood of the avüIow ; and the small knobs found at the roots of
the turnip and cabbage are formed and inhabited by another small weevil (Nedyus contractus
M.). But these injuries ai-e trivial, when put in comparison with those produced
on the young grafts of apple trees by one of the short-snouted weevils (Otiorhyuchus
vastkor Marsh.), which sometimes destroys many hundreds in one night, particularly in
the nurseries about London. This most pernicious insect is equally dreaded on the
Continent, where it destroys the young vines, often killing them the first y e a r; and is
accounted so teivible an enemy to them, that not only the beetles, but their eggs, are
diligently searched for, and destroyed: we are noAv aware that this pest has also found
its way into our graperies. Balaninus glandium does much injury to anorns, Avhich it
perforates and devours, Avhen in the larva state, like the nut weevils.
1629. The wireworm {fig. 281. a) is the gnib
o f a coleopterous insect, the E'later obscurus of
Marsham (J). This fact has been ascertained
by Mr. Paul, an ingenious agriculturist of Stars-
ton in Norfolk. The dcstmction that this gmb
produces is unfortunately too well known. It
Uves in the larva (or feeding) state upwards of
five y e a rs ; dm-ing all which time it commits its
ravages on the roots of grass and grain, particnlarly
that groAving on ncAvly broken-up land.
The trae w i r e w o rm h a s b e e n c o n f o u n d e d Avith
t h e lai-A’a {b) a n d p u p a {c) o f c r a n e flies ( T i p u -
I f ,
!r !'