Encyclopaedia Britannica; Or A Dictionary of Arts, Sciences, and ...

4. Moniliformes, moniliform, i. e, of the form of a necklace, when they are of an equal thickness throughout, but formed of a series of knobs, resembling a string of beads.

5. Capitate, capitate, i. e. with a head or knob, when they grow thicker towards the point, and terminate in a knob or head.

6. Fissiles, fissile, i. e. cleft, when they are capitate, and have the head or knob divided longitudinally into three or four parts or laminæ.

the distinguishing peculiarities of each, cannot fail to 2. Clavatæ, clavated, i. e. club-shaped, when they
create surprise. The great and almost phantastic va grow gradually thicker from their base to their point.
riety of their forms, the nice adaptation of their parts 3. Filiformes, filiform, i. e. thread-shaped, when
to the situation in which each happens to be placed, they are of an equal thickness throughout the whole of
must appear truly wonderful. In every department of their length.
nature, which comes within the reach of the human
mind, a pleasing and luxuriant variety is discernible.
The same Supreme Intelligence, which, by varying the
position of the planetary orbs with respect to the sun,
and by other seemingly simple but beautiful contri-
vances, hath produced their different length of day and
year, and alternation of seasons, is manifest in the forma
tion of the minutest insect. Each has received that
mechanism of body, those peculiar instincts, and is made
to undergo those different changes, which fit it for its
destined situation, and enable it to perform its proper
functions. The utility of many insects, such as the bee,
the crab, the silk-worm, the cochineal insect, &c. render
them both interesting and important; and a more intimate
acquaintance with the class, may enable us to add to the
number of those that are useful to man, and to improve-
ments in the management of those already known. The
havock many insects make in the vegetable kingdom,
the vexation, diseases, and destruction they occasion
among animals, should induce those who are engaged in
agriculture, and in the rearing and management of ani-
mals, to pay attention to Entomology; for the better
they are acquainted with their enemies, the abler they
must be to attack them with advantage.

Many insects undergo three very distinct changes: which circumstance, joined to the very great difference of appearance which is often met with in the male and female, and even in the neuters of some species, renders their number apparently greater than it really is, and adds considerably to the difficulty of reducing them to order.

Different naturalists have attempted to arrange them into families and genera, particularly the celebrated LINNEUS, whose arrangement is followed here. He has formed them into seven families or orders, composing his Definition, sixth class of animals, INSECTA. He defines an insect, a small animal, breathing through pores on its sides, furnished with moveable antenna and many feet, covered with either a hard crust, or a hairy skin. Before the distinguishing marks of the orders and genera can be understood, it will be necessary to enumerate and explain the terms he has given to the different parts, and the most remarkable of the epithets he has applied to them.

Head, &c.

The body is divided into Head, Trunk, Abdomen, and Extremities.

I. CAPUT, the Head, which is distinguishable in most insects, is furnished with Eyes, Antennæ, and most frequently with a Mouth.

The EYES, 2, 4, 6, or 8 in number, destitute of eye-lids, are either small and simple; or large, compound and hemispherical; or polyedral. They are commonly immoveable. They are called stipitati when placed on a stalk.

The ANTENNE are two articulated moveable processes, placed on the head.

They are either, I. Setacea, setaceous, i. e. like a bristle, when they taper gradually from their base, or insertion into the head, to their point.

7. Perfoliata, perfoliated, when the head or knob is divided horizontally.

8. Pectinata, pectinated, i. e. resembling a comb, when they have a longitudinal series of hairs projecting from them, in form of a comb.

9. Barbata, barbed, when they have little projections or barbs placed on their sides. They are either, 1. Longiores, longer than the body; 2. Breviores, shorter than the body; or, 3. Mediocres, of the same length with the body.

The MOUTH, in most insects, is placed in the under part of the head; sometimes, however, it is situated in the thorax, and in a few instances, is entirely wanting. It is furnished with, 1. Palpa, or feelers; 2. Rostrum, i. e. beak or snoot; 3. Labium, or lip; 4. Maxillæ, or jaws, placed transversely, and moving laterally; 5. Dentes, or teeth; 6. Lingua, or tongue; 7. Palatum, or palate.

Palpa, feelers, which are 4 or 6 in number, are attached to the mouth, and have 2, 3, or 4 articulations. The Stemmata are three prominent shining points on the top of the head.

II. TRUNCUS, the Trunk, to which the legs are Trunk. attached, is situated between the head and the abdomen. It is divided into, 1. The Thorax, or chest, which is the superior part; 2. Scutellum, i. e. small shield or escutcheon, which is the posterior part; 3. The Breast and Sternum, which is the inferior part.

III. The ABDOMEN, that part which contains Abdomen. the stomach, intestines, and other viscera, consists of several annular segments. It is perforated on the sides with spiracula, i. e. breathing holes. The upper part of it is termed Tergum, or back; the inferior part Venter, or belly; the posterior part Anus.

Ív. ARTUS, the extremities, are, 1. the Wings; 2. Legs; 3. Tail.

I. ALA, the wings, are two, or four. They are either,

1. Planæ, i. e. plain, such as cannot be folded up by the insect.

2. Plicatiles, or folding, such as can be folded up by the insect at pleasure.

3. Erecta, erect, such as have their superior surfaces brought into contact, and stand upright when the insect is at rest.

4. Patentes, spreading; such as are extended horizontally.

Incumbentes, incumbent; such as rest on the un
per part of the abdomen.

6. Deflexa, bent down; such as are partly incum-
bent,

Extremi

ties.

Most insects undergo three changes. An insect is Metamorat first hatched from a very small egg, and becomes a phosis. LARVA; a soft succulent animal, without wings, incapable of producing its species, slow in its motions, sometimes without feet, but more frequently with them; consuming greedily the kind of food which is peculiar to it, and which, in proper time, is changed into a

pupa.

PUPA (Nympha, Chrysalis), is firmer and drier than the larva, and is confined either by a naked membrane, or enclosed in a follicle. It is commonly without a mouth; sometimes it has feet, but more frequently

none.

1. Completa, complete in all their parts, and active; as the aranea, acarus, oniscus, &c.

2. Semicompleta, half complete, with only the rudiments of wings; as the gryllus, cicada, cimex, libellula, and ephemera.

3. Incompleta, incomplete, with immoveable wings and feet; as the apis, formica, and tipula.

4. Obtecta, covered, having the thorax and abdomen enclosed in a skin, and that either naked, or enclosed in a follicle differently composed.

5. Coarctata, confined within a globe; as the musca,

œstrus.

The pupa is converted into the imago, or the perfect insect.

IMAGO, is the perfect insect, active, furnished with antennæ, and capable of generating.

Insects are said to inhabit those plants on which they feed, and not those on which they may be occasionally found, and receive from them many of their specific names.

LINNEUS has divided the class of insects into seven orders.

Elytra.

bent, but have their exterior edge inclined towards the
sides of the abdomen.

7. Reversa, reversed; such as are incumbent, but
inverted.

8. Dentata, such as have their edges notched or serrated.

9. Caudata, such as have processes extended from their extremities like a tail.

10. Reticulata, netted; when the vessels of the wings put on the appearance of net-work.

II. Picta, painted; such as are marked with coloured spots, bands, streaks, lines or dots.

12. Notatæ, marked with specks.

13. Ornate, adorned with little eyes, or circular spots, containing a spot of a different colour in their centre. The central spot is termed pupil; the exterior one is called iris. This may happen either in the primary or secondary wings, on their upper or under surfaces. The superior wing is called primary, and the inferior secondary, to avoid confusion, as they may be at times reversed.

The ELYTRA are hard shells, occupying the place of the upper wings. They are, for the most part, moveable, and are either,

1. Truncata, truncated, when shorter than the abdomen, and terminated by a transverse line.

2. Spinosa, or prickly, when their surfaces are covered with sharp points or prickles.

3. Serrata, serrated, when their edges are notched.
4. Scabra, rough, when their surface resembles a file.
5. Striata, striated, when marked with slender longi-
tudinal furrows.

6. Porcata, ridged, when marked with elevated ridges.
7. Sulcata, furrowed.

8. Punctata, marked with dots.

9. Fastigiata, when formed like the roof of a house. Hemelytra. The HEMELYTRA, as it were half-elytra, partaking

Halteres.

Sexes,

I. COLEOPTERA, (from xλtos, "a sheath," and Classificapartly of the nature of crustaceous shells, and membra-seer," a wing"), are such insects as have four wings, tion. naceous wings; being formed of an intermediate sub

stance.

HALTERES, or poisers, are small orbicular bodies placed on stalks, situated under the wings of insects of the order Diptera.

II. PEDES, the Legs. They are divided into, 1. Femur, or thigh, that part which is joined to the trunk; 2. Tibia, or shank; 3. Tarsus, or foot; 4. Ungues, hooks or nails; 5. Manus, (chela), hands or claws, simple, with a moveable thumb, as in the crab.

The hind-legs are termed, 1. Cursori, formed for running; 2. Saltatorii, formed for leaping; 3. Natatori, formed for swimming.

III. CAUDA, the Tail, which terminates the abdomen, is, 1. Solitaria, i. e. single. 2. Bicornis, i. e. twohorned or double. 3. Simplex, simple, i. e. unarmed. 4. Armata, i. e. furnished, 1. with Forceps or Pincers; 2. with Furca, a fork; 3. with one or more Seta or bristles; 4. with an Aculeus, or sting, either smooth or barbed. A sting is a weapon, frequently hollow, with which some insects are furnished, through which they discharge a poison into the wound they inflict.

The SEXES of insects are commonly two, male and female. Neuters are to be met with among those insects which live in swarms, such as ants, bees, &c.

the upper pair of which are elytra, or crustaceous shells, which, when the animal is at rest, shut, and form a straight suture down the back.

II. HEMIPTERA, (from us, "half," and go, "a wing"), containing such insects as have four wings, the superior part being half crustaceous, and incumbent, and a mouth or beak bent toward the breast.

III. LEPIDOPTERA, (from Ass," a scale," and go, "a wing"), containing such insects as have four wings covered with minute imbricated scales, a hairy body, and a mouth furnished with an involuted spiral tongue.

IV. NEUROPTERA, from gor, a nerve," and leger," a wing), containing such insects as have four naked wings, marked with veins crossing one ano. ther like net-work; the tail unarmed.

and

V. HYMENOPTERA, from inr,

a membrane,"

go, "a wing"), containing such insects as have four membranaceous wings, and a tail furnished with a sting.

VI. DIPTERA, (from duw, "two," and legov, "a wing"), such as have two wings and poisers.

VII. APTERA, (from, without," and gor, a wing"), such as have no wings or elytra in either sex.

T 2

CHARACTERS

Coleoptera.

CHARACTERS OF INSECTS.

I. COLEOPTERA.

The insects belonging to this order are formed into four divisions.

1. Those that have the antennæ clavated,

and thickened towards their exterior side. 2. Those that have the antennæ moniliform. 3. Those which bave the antennæ filiform. 4. Those which have the antennæ setaceous.