Category: Science - Biology

An Introduction to Entomology: Vol. 3 or Elements of the Natural History of the Insects

What is an insect? This may seem a strange question after such copious details as have been given in my former Letters of their history and economy, in which it appears to have been taken for granted that you can _answer_ this question. Yet in the scientific road which you are...

Chapters

27. LETTER XXXV.

As the _head_ of insects is the principal seat of the organs of _sensation_, so is the _trunk_ of those of _motion_; and in it are contained the muscles by which they are moved:...

25. vii. We now come to a circumstance which will detain us longer,

namely, its _articulation with the trunk_, or rather with its anterior segment, the _prothorax_.--M. Cuvier makes _two_ principal kinds of articulation of the head upon the prot...

2. LETTER XXIX.

On a former occasion I gave you a general idea of what has been called, perhaps not improperly, the _metamorphosis_ of insects[61]; but since that time much novel and interestin...

1. LETTER XXVIII.

What is an insect? This may seem a strange question after such copious details as have been given in my former Letters of their history and economy, in which it appears to have...

11. ix. As insects often live longest in the state we are treating of,

I shall say something next upon the _age_ of larvæ, or the period intervening between their exclusion from the egg and their becoming pupæ. This is exceedingly various, but in e...

22. LETTER XXXIII.

Having shown you our little animals in every state, and traced their progress from the egg to the perfect insect, I must next give you some account of their _structure_ and _ana...

7. i. With legs only, and with or without an anal proleg

I should next say something upon the spiracles, or breathing-pores, or any other external apparatus for the purpose of _respiration_, in larvæ; but I think it will be best to re...

20. ii. The sexes of insects vary (but more rarely than in colour) in

their _sculpture_ also, and _pubescence_. Thus the elytra of the females of many of the larger water-beetles (_Dytiscus_) are deeply furrowed, while those of the males are quite...

29. part I call the pulley is merely an upper sinus of the large orifice

that receives the pedicle of the abdomen. The shape of these orifices, both of the trunk and abdomen, varies in different genera: thus, in the bee it is triangular, with the ver...

4. ii. Those which resemble the perfect insect, except that they

i. Spiders, _Phalangia_, scorpions, lice, _Poduræ_, sugar-lice (_Lepisma_), mites, centipedes, millepedes, &c. come under the _first_ subdivision. The larvæ of the first six tri...

15. iii. Those pupæ which are inclosed in the thick and opaque skin of

the larva, through which no _trace_ of the perfect insect can be _discovered_. These, which Linné termed _coarctate_ pupæ, include a large proportion of the _dipterous_ genera;...

16. vi. Though the pupæ of the second great division are usually not

locomotive, yet I must not omit some notice of their _motions_. As the legs of insects in this state are folded within a common or partial integument, of course none of the pupæ...

12. xv. 37-48, (who has satisfactorily ascertained that it is the true

larva of a _Tinea_ of Linné, but of a different habit from that of most subcutaneous ones), has no true legs, and eighteen prolegs without any claws. Another subcutaneous larva,...

21. v. All the differences I have hitherto noticed between the sexes

of insects occur in their _bodily_ structure; but there are others of a somewhat higher description observable in their _character_. You may smile at the idea of character in be...

26. xvii. 545, seems not to regard these as palpi; but from their tubular

[1238] For Mandibles of _Locusta_ see PLATE VI. FIG. 6. c´. of _Lampyris_ Oliv. _Ins._ no. 28. _t._ i. _f._ 1. of _Buprestis_, _Ibid._ no. 32. _t._ iii. _f._ 17. of _Lucanus_, _...

18. LETTER XXXII.

When the insect has quitted the exuviæ of the pupa, it has attained the last stage of its existence. It is now termed an _Imago_, or perfect insect; and is capable of propagation.

9. vii. You will require no stimulus to induce you to attend to the

subject I am next going to enter upon,--the _Moulting_, namely, of Larvæ; or their changes of skin. This, indeed, is a subject so replete with interest, and which so fully displ...

5. i. The prolegs of almost all Lepidopterous larvæ are furnished

with a set of minute slender horny hooks, crotchets, or _claws_, of different lengths, somewhat resembling fish-hooks; which either partially or wholly surround the apex like a...

24. iv. The integument of insects is often clothed, either partially or

generally, with _pubescence_, or hairs of various kinds--a circumstance which seems to have more than one object. In _Parnus_, _Heterocerus_, _Gerris_, _Argyroneta aquatica_, an...

8. v. Amongst other qualities which attach to larvæ, we must not

omit to say something concerning their _Colour_. For though those which live in darkness, in the earth, in wood, in fruits, &c. are, with few exceptions[454], of an uniform whit...

17. i. Like the perfect insect, except in proportion and number of

iii. _Nympha._ Under this denomination are included all insects that undergo only a partial metamorphosis, and are active in their pupa state, corresponding with the _Pupa semic...

23. LETTER XXXIV.

Before I confine my observations to the _head_ of insects, which I propose to consider separately in the present letter, I must premise a few words upon their _body_ in general,...

28. LETTER XXXVI.

The _abdomen_ of insects, which we are next to consider, is the _third_ great section of the body, and is the seat of the organs of generation, as well as of a principal part of...

19. i. In some species the sexes are either partly or wholly of a

different _colour_. Thus, in the order _Coleoptera_, the elytra of the male of _Rhagium meridianum_ F. are testaceous, and those of the female black. _Leptura rubra_ of Linné, w...

14. i. The first subdivision will include the pupæ, if they may be so

called[563], of insects of the _Aptera_ order, and of the class _Arachnida_: as, lice, _Poduræ_, _Lepismidæ_, centipedes, millipedes, mites, harvest-men, spiders, scorpions, &c....

10. viii. And this leads me to a subject to which I am desirous now to

bespeak your attention,--the _Growth_, I mean, and size of Insects in this state. As to _size_, larvæ differ as much as insects in their perfect state: these last, however, neve...

3. LETTER XXX.

The _Larva_ state is that in which insects exist immediately after their exclusion from the egg (or from the mother in ovo-viviparous species), in which they usually eat voracio...

13. LETTER XXXI.

We have now traced our little animals through their egg and larva states, and have arrived at the third stage of their existence, _the Pupa State_. This, to include all, can onl...

6. i. With a corneous head of determinate shape (coleopterous and