Chapter VIII: Part 8

ORDER: Diptera. SECTION: Athericera. FAMILY: Syrphidæ, _Leach._.

GENUS. ERISTALIS, _Meigen_. Musca, _Drury, &c._

ERISTALIS CINCTUS. Ater; thorace punctis quatuor fasciâque posticâ
sulphureis, abdomine castaneo fasciâ mediâ sulphureâ. (Magn. Musc.
carnariæ.)

SYN. Musca Cincta, _Drury, App. vol._ 2.

HABITAT: Jamaica.

Head large and black. Eyes brown (antennæ broken off). Thorax black, with
two yellow spots next the head, and one on each side, at the base of the
wings, with a yellow line crossing it next the abdomen. Scutellum
chesnut-coloured. Abdomen chesnut-coloured at the base, with a yellow
ring crossing the middle; at the extremity golden green. Legs and breast
black. Wings transparent.

{104}ECHINOMYIA PILOSA.

Plate XLV. fig. 7.

ORDER: Diptera. SECTION: Athericera. FAMILY: Muscidæ.

GENUS. ECHINOMYIA, _Dumeril_. Tachina, _Fabr._ Musca, _Drury_.

ECHINOMYIA PILOSA. Atra; setis rigidis numerosissimis obsita, alis opacis
fuscis, capite brunneo. (Echin. hirtâ paullo minor.)

SYN. Musca pilosa, _Drury, App. vol._ 2.

Tachina hystrix, _Fabr. Syst. Antl._ 310. 8. _Weidemann Auss. Zw. Ins._
2. 284.

HABITAT: Jamaica.

Head red brown. Antennæ short and thick, without hairs. Thorax and
abdomen entirely covered with thick black hairs, or rather bristles, when
compared with the size of the insect. Wings opake and brown, not
transparent. Breast black, covered with black bristles. Legs black,
spinose.

PLATE XLVI.

MYRMELEON LIBELLULOIDES.

Plate XLVI. fig. 1.

ORDER: Neuroptera. SECTION: Filicornes. FAMILY: Myrmeleonidæ, _Leach_.

GENUS. MYRMELEON, _Linn. &c._

MYRMELEON LIBELLULOIDES. Alis fusco punctatis maculatisque corpore nigro
flavoque maculato. (Expans. Alar. 4 unc. 9 lin.)

SYN. Myrmeleon Libelluloides, _Linn. Syst. Nat._ 1. 2. _p._ 913. 1.
_Fabr. Ent. Syst._ 2. 92. 1.? _Latr. Gen. Crust. & Ins._ 3. 191.

Libella turcica major alis locustæ, _Pet. Gaz._ 6. _t._ 3. _f._ 1.

HABITAT: Smyrna (_Drury_). "In Europa australiori et per totam Africam"
(_Latreille_).

Head dark yellow, divided by a black line, which runs along it from the
thorax. Antennæ black and clubbed, small at the base, and gradually
increasing to their extremities. Thorax brownish yellow; having a black
line running along its upper part, and two small black spots at the base
of the superior wings, being covered with greyish hairs. Abdomen about an
inch and a quarter long, yellow, with a black line on the top, and one on
each side; the male having two small horny tails issuing from the
extremity. Wings membranaceous and pellucid (the inferior ones being as
long as the superior), and elegantly adorned with a great number of dark
spots of various shapes and sizes.

Fabricius gives the Cape of Good Hope as the habitat of this species, referring not only to the present figure, but also to that given in Vol. 3. Plate 41. which is said by Drury to have been brought from Sierra Leone. This is the more inexcusable, because Drury expressly observed in a note, "There is a species found near the Cape of Good Hope very much like this, but distinctly different," although in the synoptical appendix to the third volume, he gives the large species from Sierra Leone as a variety of M. Libelluloides.

{105}EUPTILON ORNATUM.

Plate XLVI. fig. 2.

ORDER: Neuroptera. SECTION: Filicornes. FAMILY: Myrmeleonidæ, _Leach_.

GENUS. EUPTILON, _Westw. Gen. Nov._ Hemerobius, _Linn. Drury._

EUPTILON ORNATUM. Viride, thoracis puncto antico abdomineque lineâ
dorsali nigris, alis hyalinis venis numerosissimis, strigisque duabus
obliquis obscuris. (Expans. Alar. circ. 3 unc.)

SYN. Hemerobius ornatus, _Drury, App. vol._ 2.

HABITAT: Dinwiddie, in Virginia.

Head dark green. Antennæ pectinated or combed. Eyes black. Thorax dark
green, with a black patch next the head. Abdomen dark green, with small
rings of yellow, and a small black line running along the upper side from
the thorax to the extremity. Wings membranaceous and pellucid, or
transparent, of equal length; the superior ones having two small
transverse black stripes placed near their posterior edges, at about half
an inch distance from each other.

Latreille, in his Genera Crustaceorum et Insectorum, Vol. 3. p. 199, after describing the genus Chauliodes belonging to the family Hemerobiidæ, observes, "Congenerica videntur insecta a Dom. Drury iconibus vivis expressa, tom. 1. Pl. 46. Fig. 2. 3." I have never seen the present species, but from the admirable accuracy of Moses Harris (by whom the figures were drawn) it is evident that the neuration of the wings of this species is identical with that of Myrmeleon, agreeing especially with the insect represented at Fig. 4. of this plate, and exhibiting the irregular longitudinal nerve below the subcostal nerve and the strong furcate nerve running along the middle of the wing; whilst, at the same time, the neuration is quite unlike that of Fig. 3. Hence I have no hesitation in placing this insect in the family Myrmeleonidæ. It however disagrees with the genera of which that family is composed, viz. Myrmeleon, Linn. (Myrmecoleon, Burm.) Ascalaphus, Fabr. and Nymphes, Leach, in having bipectinated antennæ, so that I have been compelled to establish a new genus for its reception. Can it be possible that, according to the not uncommon practice of the time, the specimen had been mended, and that pectinated antennæ had been substituted in the stead of the ordinary ones of a Myrmeleon?

CHAULIODES VIRGINIENSIS.

Plate XLVI. fig. 3.

ORDER: Neuroptera. SECTION: Filicornes. FAMILY: Hemerobiidæ, _Leach_.

GENUS. CHAULIODES, _Latreille._ Hemerobius, _Linn. Drury_.

CHAULIODES VIRGINIENSIS. Capite thoraceque nigris fulvo punctatis, alis
latis hyalinis venis nigro punctatis. (Expans. Alar. 3 unc.)

SYN. Hemerobius Virginiensis, _Drury, App. vol._ 2.

Hemerobius pectinicornis, _Linn. Syst. Nat._ 1. 2. 911. 1.? _Pal. Beauv.
Ins. Afr. et Am. Neur. pl._ 1. _f._ 2.?

HABITAT: Virginia.

Head black, with a yellowish spot in the front, and another on the top.
Eyes greyish, and shining like polished bell-metal. Antennæ pectinated or
combed, and longer than the thorax. Ocelli three. Thorax black, with
three small yellowish spots on the posterior part. Abdomen almost black
at top, {106}and underneath of a greyish yellow (as are all the legs),
having two short setæ or tails at the extremity. Wings membranaceous and
transparent; the nerves appearing, when viewed by a magnifier, to be
black and white, like the quills of a porcupine. Inferior wings shorter
than the superior.

Drury has figured the wings as of an uniform colourless appearance, which induces me to consider that it may be distinct from the Linnæan H. pectinicornis, that species being described by the great Swede with "_signaturis_ nervisque fuscis albo subarticulatis." From the paleness of the present species it is evident that the transverse nerves connecting the longitudinal ribs of the wings in the typical species of this genus have been overlooked, especially as the longitudinal nerves are correctly represented. This genus and Corydalis, seem to form a connecting link between Hemerobius and Perla.

MYRMELEON AMERICANUM.

Plate XLVI. fig. 4.

ORDER: Neuroptera. SECTION: Filicornes. FAMILY: Myrmeleonidæ, _Leach_.

GENUS. MYRMELEON, _Linn, &c._

MYRMELEON AMERICANUM. Thorace griseo nigro notato, alis hyalinis fusco et
luteo punctatis, punctis nonnullis lineam centralem longitudinalem
formantibus, abdomine fusco. (Expans. Alar. 5 unc.)

SYN. Myrmeleon americanus, _Drury, App. vol._ 2.

HABITAT: New York.

Head black, front grey and hairy. Mouth with four long palpi. Eyes dark
brown, almost black. Antennæ black, and as long as the thorax; being
small at the base, and increasing in size to their extremities. Neck
yellowish, striped with black, and covered with longish grey hairs.
Thorax yellowish, with black stripes, and covered with long grey hairs.
Abdomen, which is full an inch and a half long, brownish-coloured, and
darker on the sides; being furnished at the extremity with two short
hairy tails, seemingly of a horny substance. Wings of equal length,
membranaceous and transparent, having a great number of small spots
thereon of a dark brown colour; the superior ones being most spotted.
Legs black, and covered with grey hairs; each of them being furnished at
the tips of the tibiæ with two long spines that bend inwardly towards
each other.

----

LIBELLULIDÆ, Pl. 47 & 48.

All the insects represented in these two plates belong to the genus Libellula of Linnæus, or the family of Dragon-flies, Libellulidæ. When the original edition of this work was published, there was no English work in which the natural history and curious transformations of this tribe of insects were detailed. Our author, therefore, in order to supply the deficiency, published the following interesting series of observations upon the subject:--

"As I have not met with any English author who has given the natural history of the insects delineated in these two plates, I shall make no apology for its introduction; {107}the frequent opportunities I have had of observing their mode of life and action, together with the many singular circumstances observable in both, being motives for its publication too powerful to be resisted.

"It is not easy to determine whether they should be ranked among the water insects, or those of the land, nor shall I attempt here to ascertain it; my present business being only to relate the several circumstances attending them during their respective states in which they are passing from the egg to the complete animal: and although these observations have been confined to our English ones, yet they so exactly agree and coincide with those of foreign countries, (as my correspondents have assured me), that their nature and behaviour appear to be just the same; so that what is observable in ours, is at the same time applicable to the whole genus wherever found.

"If we take a cursory view of the different ranks of animals that inhabit our globe, we shall hardly find one that can excite our wonder and astonishment more than this genus; nor is it from that general ignorance of the insect world, that reigns so strongly in these kingdoms, that I am emboldened to say this; but if we reflect that the beasts, birds, and reptiles are furnished with powers for living only in the air, and that even the amphibious tribes can perform the office of respiration only in that element: if we also consider that fishes, on the contrary, are unable to respire but in water, and when deprived of that must certainly perish, we cannot but conclude that all these animals are most wisely fitted with means and faculties for filling up the respective orders and ranks wherein they are placed. But let us cast our eyes on the subjects I am about to describe, and there behold a tribe of beings, who, as soon as they leave their eggs, subsist for a certain number of months, (I had almost said years), creeping and swimming in the liquid element; are there invested with organs and powers for existing and weathering out the utmost severity and intemperance of the winter; that afterwards as the spring and summer advances, and the period arrives when they are to appear in other forms, in the space of about half an hour those very organs and powers that before enabled them to live under water should be so entirely altered, the very natures and abilities of the creatures so changed as to permit them to quit their former element and place of residence, insomuch that all the remaining part of their lives is spent in the open air, furnished with wings, and flying about in the full glee of wanton liberty; that in a very few weeks after, having performed the business of generation, the same animals should die of mere old age, with their wings quite ragged and worn out, their strength exhausted, and all the powers of their bodies lost by a total imbecility and weakness, which but a little before enabled them to transport themselves through the air with the swiftness of a bird. If, I say, we reflect on all these circumstances, we cannot but allow them to be objects of a very extraordinary nature, and well adapted for leading the mind to the contemplation of their supreme Author, who has thought proper to exhibit to us these kind of insects, thus differing from almost all the animals in the creation.

{108}"They have been variously named by different authors, owing perhaps to the time when they wrote, or the progress natural history had made in the world. Some have called them by the name of Dragon Fly, others Adder Bolt, Balance Fly, Perla, Libellula or Libella. I shall prefer the last, as conveying an idea well known to English adepts. The caterpillars of them all live in ponds and stagnant waters (that are undisturbed by cattle) during the greatest part of their lives, and make their appearance under three general forms. The first is shewn by Fig. 1. 1.; the second by Fig. 2.; and the third by Fig. 3. See Plate 47. As these are the shapes in which they all appear, it will not be improper to mention each particularly.

"The two caterpillars at Fig. 1. 1. Plate 47, belong only to or produce those that sit at rest, with their wings erect, (see Plate 48. Fig. 2.), and differ from both the others not only in size but in the roundness and slenderness of their bodies; at the extremity whereof they are furnished with three tails, each of which upon examination being found to be a kind of feather, and is an appendage that neither of the others have. Their behaviour also in the water is different from the others, being enabled to twist and bend their bodies in a more circular manner. [Subfamily Agrionides.]

"The second sort of caterpillars, at Plate 47. Fig. 2. are much shorter and thicker in their bodies than either of the others, producing those Libellas with flat bodies, as Plate 47. Fig. 4. and 6. and Plate 48. Fig. 1. and 5. These are, of all others, the most disagreeable in their appearance; most of them having their bodies and legs very rough and shaggy, and of the exact colour of mud. Others appear of a dirty green, and very unpleasing hue, a colour that in general reigns among them all; for none can boast of any beautiful appearance while in this state, unless the different shapes here exhibited can be called so. Indeed the beauty and symmetry, so apparent in their complete states, make ample amends for the want of it in this; all of them in general being then very beautiful, discovering colours superior to art. [Subfamily, Libellulides. Genus, Libellula.]

"The caterpillars of the third sort (see Plate 47. Fig. 3.) are very different from the preceding, being the size of the figure, with the abdomen flat at bottom and rounding at top, longer and slenderer than those at Fig. 2. but not so much as those at Fig. 1. 1. These produce those large Libellas with long slender bodies, who sit at rest with their wings expanded, as Plate 47. Fig. 5. [Subfamily, Libellulides. Genus, Æshna.]

"Under these three forms are all the caterpillars of Libellas found, there being but little difference in the colours or marks of the respective tribes; the various sizes and shapes being the chief observable circumstances attending them. They are all furnished with six legs, and have each of them four little membranaceous substances issuing from the back, or upper part of the thorax, that are the follicles, or cases, wherein the wings are inclosed. When the young caterpillars issue from their confinement in the eggs, there is no appearance of these cases, nor till a considerable time after; but as they arrive to a maturer state they become more conspicuous, and, like the young leaves of trees that open {109}and expand themselves on the arrival of the spring, their appearance increases, till having approached the period when they are to forsake their former habitations and become inhabitants of the air, these wing-cases have then arrived to their due size, and carry the appearance in which they are here seen. They are all of them, from the largest to the smallest, armed with a strong offensive weapon, which serves them, and is indeed the means they are endued with, for obtaining their food. This weapon being placed in the under part of the head, just beneath the mouth, I have displayed in Fig. 1. and 3. of Plate 47. where it appears just in the same manner as when they are endeavouring to catch their prey. In the largest figure at 1. and also in Fig. 2. it appears contracted and shut up, as when at rest. The strength and power that these animals discover in the use of this instrument is very singular and extraordinary. There are two joints to it, one about the middle, the other underneath the mouth, close to the throat; and in some (particularly all those of Fig. 2.) when it is closed or contracted, it appears fastened to the face of the creature, by fitting it so exactly as to form a perfect mask; covering the mouth, and reaching almost as high as the eyes. In others it is made to fit only the under part of the mouth, and when at rest is drawn up close underneath it. At the extremity of those that are extended may be observed two very strong and remarkable fangs; that, shutting over each other, form a pair of forceps, of such strength that few, if any of their captives, can escape if once inclosed therein. [This organ is the greatly developed lower lip of the larva, and is analogous in its structure to the same part in the imago.]

"The motion of these creatures in the water, particularly those of the largest size, is very slow; seldom exercising any swiftness or activity, unless they are disturbed and threatened with danger, in which case they can transport themselves to places of more security with the quickness or agility of a fish; but, in general, they appear to have so little inclination to move, that I have often seen them (I mean those that I have kept in glass bowls) remaining in their respective places above a week together, and could not discover the least motion in them, unless under the circumstance above mentioned, or when they had seen their prey and were advancing to seize it. The caterpillars of Fig. 1. 1. and 3. generally fix themselves to some little stick or straw, &c. that they find in the water, and there remain, as I said before, without stirring. Those of Fig. 2. are more frequently seen in motion among the thickest part of the roots and plants that grow there, routing and searching for those small animals inhabiting that part, which are their proper food. This aversion to motion, so apparent in those of No. 1. and 3., appears to me to be the effect of an extraordinary cunning and sagacity; and may be considered as the principal means by which they obtain their prey: for while they continue thus motionless in the water, the small animals, who constitute their proper food, approach them with less fear than they would otherwise do, not suspecting their grand enemy lies upon the watch to seize them the moment they come within his reach; but no sooner has their insensibility of danger brought them within a small distance of those destructive weapons (mentioned before, being placed under their mouths) but that very instant they dart upon them with {110}the utmost rapidity, suddenly throwing out their forceps, and seizing them with as much eagerness as a pike does the unwary gudgeon; they then bring their forceps up to their mouth with their prey in it, and feast on their captive prisoner. Nor is their voracious nature less astonishing; and the greediness with which the large ones seize other small animals would hardly gain belief among persons entirely ignorant of this study. I have seen one of them, in less than an hour's space, devour three insects, each of which was full two thirds as big as itself; but, in general, the small ones are the sacrifices made by the greater; wherein I must observe, that when they have got a caterpillar of the small Libellas in their forceps, such as those of Fig. 1. Plate 47., they leave no part uneaten, except the three tails, which they let fall to the bottom, as perhaps not having substance in them sufficient to afford them proper nourishment; for as their food consists altogether of animals less than themselves, they neither spare the caterpillars of the lesser Libellæ, nor confine themselves to those belonging to other tribes. They will eagerly prey upon the different kinds of Cads, or caterpillars of the Phryganeæ; great numbers of whom, at certain seasons, quit those husks or cases they make and swim about, with less fear and dread than in the early part of the spring. I have also seen the caterpillars of the Notanecta's or Boat-flies devoured by them, and not seldom the small blood-worms, as they are called. In short, there are but few of the lesser animals that live in the water, but when once they get within the reach of their instruments will certainly fall victims to these freshwater Leviathans.

"I could never observe that these caterpillars ever threw off any exuvia, or skin, in their progress from the egg to the complete animal, as most other insects do that live in the open air; neither could I ever perceive any difference between the caterpillars and chrysalis's of this genus in their outward forms[31]: the same voracious behaviour in seizing and devouring their prey, reigning both in one and the other; but that they internally undergo some material alteration, when passing their respective states, is what I do not entertain the least doubt of; as the organs of respiration during the creature's life in the water, appear to me to be under a necessity of receiving a great alteration, when they are to perform the same office in so different a medium as the air; nor can I suppose this business to be done in so quick and sudden a manner, as the short space of time in which the creature would then be passing from the caterpillar state to the perfect one would permit, without having the intestines prepared, as it were, and fitted by some previous change. However, as this is conjecture only, I shall dwell no longer on this head, my present purpose being to point out and describe their general circumstances and behaviour.

"When the caterpillars of the respective species have arrived to their full growth, and nature informs them they are to quit their former element of water, for one wherein they are to appear invested with very different powers, they prepare for this extraordinary change; and, creeping up the sticks, straws, or plants they find for their purpose, whose tops grow out of the water, they entirely quit that element, and, stopping at about six or {111}eight inches above its surface, there fix themselves, and continue some time, till their internal form, growing too big to be confined within the skin, that a few minutes afterwards will be entirely thrown off, on a sudden, that part of it that covers the thorax, splits or bursts on the upper side, and the creature, pushing out its head, next disengages its fore legs, which fastening to any substance within its reach, draws gently the remainder of its body and legs entirely out, just as a man draws his leg out of a boot, leaving its slough or skin sticking in its place, and in the exact form wherein it appeared itself but a few moments before. Having thus quitted its former covering, it waits for the wings to expand themselves, and grow to their proper size, being before confined within those small cases I mentioned were placed on its back. In about half an hour, if the weather is favourable, this extraordinary operation is completed; and the wings having arrived to their proper size, the creature generally makes an effort to try its strength, well knowing, that if it fails in attempting to fly without being endued with a sufficient degree of it, it must certainly fall in that water it lately quitted, and there perish; but having made several motions with its wings, and finding its power equal to its desire, it suddenly flies into the air, and there fills up a character, as different from the former as one element is from the other. At the time this change is accomplishing, the instrument or weapon for catching their prey, before mentioned, by an effect of nature, totally disappears, and not the least vestige of it then remains; the mouth, indeed, is furnished with jaws, and those of a very extraordinary form (dividing themselves both horizontally and perpendicularly), but no part of them appear extended beyond the rest, or have the least appearance of being furnished with an instrument like what they had in their former state.[32]

"Hitherto I have considered these creatures only in their infant or incomplete states; wherein the faculties and powers they are endued with, are entirely different from those of their perfect and complete ones. In the former I have described them swimming and grovelling about in the water, preying upon the lesser kinds of insects, being incapable of subsisting for any length of time out of that element; in the latter we must view them capable of flying in the open air, and conveying themselves from place to place. If they are then confined to the limits of a small pond, they are now capable of roving from tree to tree, and from field to field, darting and skimming along with all the rapidity and seeming joy, that a being sensible of, and exulting in its own powers, can be supposed to do; in short, we {112}must now view them in shapes so distinct and different from their former ones, that they hardly seem to bear any relation to each other, except in their nature and appetites; for although they appear in a far more elegant dress than when in their caterpillar states, yet these are just the same, the same voracious inclinations subsisting now as formerly; hunting after, and preying upon, the lesser genera, with the same eagerness and desire as they did when inhabitants of the water. Incredible numbers of small moths, bees, flies with four and two wings, are the daily sacrifices offered to the insatiable appetites of these hungry gluttons; and where they devoured one insect in the water they now destroy a hundred, if the mildness of the season will permit them to range about in quest of them. In rainy weather they seldom or ever move, nor when the wind is very strong and boisterous. Indeed, it is not to be wondered at. The small insects, who are their proper food, being by the same reasons prevented from being abroad, consequently are an impediment to those motives, that so strongly induce the Libellas to fly about. During such inclement times they generally shelter themselves from the wind, &c. being suspended by their feet in a perpendicular position on some twig, that is remote and separate from any boughs, waiting in that manner, without motion, for better weather and sunshine.

"I am strongly inclined to believe, that the greater part, if not all the Libellas, are two years in passing from the egg to the complete animal. But as this is a circumstance I do not remember to have seen in any author, I shall not attempt to establish my opinion as an absolute truth. I shall mention my reasons for this belief, and leave it to every person either to confirm or confute it, as his observations shall hereafter give him an opportunity.

"In order to do this, it would be necessary I should mention the times when each species first makes its appearance here in England. But as this would not only take up too much of the reader's time, (there being at least twenty-two of them) but it would likewise be impossible to be understood by any, but the experienced adept, unless I gave figures of them all; I shall therefore content myself with observing, that the Libella figured in Plate 47. Fig. 5. though found in America, about New York, &c. is nearly the same with our English one, differing but a very little from it, and which I have inserted chiefly as an instance to illustrate this subject. Ours is the last species but one, that comes forth in the summer, breeding only once a year, appearing about the 2nd of August. Therefore, to elucidate this point, suppose we allow a fortnight or three weeks from that time for all the Libellas of this species to make their appearance in, that nature intended should be bred that year; but in order to set this matter in the strongest light, I shall allow a month to that purpose. If, therefore, the Libellas were only one year in passing from the egg to the perfect state, we might justly conclude, that after the 2nd of September, (a month from the time of their first appearing) all of this species would have arrived to their complete states; and that none of their caterpillars could be found in the waters after that time, by reason they had all quitted that element, and were become flying insects. This, I say, is the conclusion we might fairly, and without presuming on the matter, make. But this is {113}very far from being the case. For let any one examine stagnant waters at any time during the months of August, September, or October, and from thence in any part of the following winter, and he will find these very caterpillars at any of those times: and this, not in any one particular year, but they will be found also in any one whatever, fully fed, and of the largest size. Nor are the caterpillars of this species the only ones to be found fully fed. Those of No. 2. belonging to the flat-bodied Libella, will also be found very plentifully, many of them being of the first magnitude, together with numbers of the same species, very young according to the time of year when sought for; and appearing to have been hatched from those eggs that were laid by parent insects in the spring; for such I must conclude them to be, how else can we account for their smallness, at the same time that we may find others of the largest size? We must not suppose there can be this difference of size in the same species, owing to some eggs having been laid three weeks or a month sooner than others; that, being so short a space of time as not to allow it possible for one of those caterpillars to attain its full size, (and all the species of flat-bodied Libellas appear within a month of each other.) Nor can we be so deceived as to mistake a species of the long-bodied caterpillars, for one of the short-bodied; the difference being extremely apparent at the first glance.

"These reasons appear to me so convincing, I should have thought myself inexcuseable to have passed them over in silence, when I was giving the history of these animals. I shall therefore think myself happy to have this circumstance corroborated by future experience, or rectified and cleared up, if found to be an error. I shall only say, I have dwelt the longer on it, as it is an observation I never heard of before. I have likewise singled out the largest Libella, and the flat-bodied ones for its illustration, as being more conspicuous by their size, and easier to be observed than those of the smaller sorts.

"The two principles of hunger and lust, so apparent through the animal kingdom, are in no class or tribe more manifest and visible than in these insects. The former I have described and explained through their different states; it remains for me to shew the manner in which they obey the calls of the latter. And herein I must observe, that the different manner in which the act of copulation is performed, depends on the difference of the respective kinds; the organs of generation being placed in different parts of the body, according to the distinct species. All the flat-bodied ones have those parts placed in common with most other insects, at the extremity of the tail. In all the slender-bodied ones, the organ of the male is placed next the breast, close to the part where the thorax and abdomen unite; while the same organ in the female lies in the very extremity of the tail, and the singular manner of these creatures coupling is a circumstance worthy of observation.

"As soon as they have arrived to their perfect state, the males seek out their mates, in order to propagate their species; for this purpose they frequent ponds and standing waters, places where the females generally harbour, and when the male in the course of his flight comes within a certain distance of her, if it be one of that species whose sexual parts {114}in both sexes are placed in the tail, he immediately flies to her, and fixing himself by his feet to the hinder part of her abdomen, bends his body round her tail, and performs the business of generation, both flying about all the time this act is performing; the whole transaction not exceeding the space of half a minute. Within a few hours after, the female, thus impregnated, begins to lay her eggs in the following manner. She singles out a leaf, grass, or some such matter, that is floating just below the surface of the water, in some pond, and, hovering in the air about a foot above this spot, on a sudden she descends, and dips the extremity of her tail in the water, at which instant she discharges an egg, that at the moment of its emission is inveloped in a glutinous liquid, sufficiently tenacious to enable it to adhere firmly on the floating substance above-mentioned without sinking. In this manner she continues depositing them till she has discharged the proper quantity, hovering in the air all the time, and emitting them as fast as the pendulum of a clock performs its vibrations; placing them close to one another in no regular or exact order. Whether she discharges at one time all her quantity of eggs, or only those that were fecundated and ready for emission, waiting to have the remaining eggs within her again fecundated by the male, or whether the first act of copulation sufficiently impregnates the whole quantity which she discharges at different times, as nature ripens them, is a circumstance I cannot determine. However this may be, it is certain she does not discharge them all at once; but comes again to the same place, when those within her are ready for emission, and there lays them in the same manner as at first.

"In this manner all the flat-bodied Libellas copulate and lay their eggs; the others, which are formed with slender bodies, behave very differently in every circumstance; for in each of those species, when the male has singled out its mate, he flies to her, and by means of two little bony substances placed at the end of his tail, issuing on each side, and composing a kind of forceps, he fixes himself to the forepart of her neck, close behind the head, the female discovering no sign of fear while he is performing this action; having fixed himself in this position, he remains there several days, sometimes appearing with his body quite erect, at other times bending himself, and settling with his legs on the same substance she may happen to alight on, without ever quitting his hold; but flies through the air, thus united, wherever the fancy or inclination of the female disposes her to go. This behaviour we must consider as a prelude to copulation, for that is not performed till a considerable time after they are thus united; and therefore I look on it as a wooing, or act of courtship in the male. But having remained a sufficient time in this manner, that is, till the female is disposed to receive him, she bends her tail round to that part where I described the organ of generation to be placed in the male, and, being still held fast by the neck, in that attitude they perform the mandate of nature. This action being over, that in the smaller kinds takes up a considerable space of time (for I have known them in this posture above eighteen hours) the female soon after begins to lay her eggs. She flies to some rush, reed, or other plant growing in the water, and settling close to its edge dips {115}the end of her tail a little below the surface, and fixes her eggs to the rush or substance she is settled on; which, by means of the glutinous matter all eggs of this kind are surrounded with, adheres sufficiently fast, and there remains till the heat of the sun has brought the young animal into life; which immediately on quitting its confinement sinks to the bottom, or repairs to the place where nature directs it to seek out its food.

"In this manner all the slender-bodied tribe behave, differing only in some particular circumstances; as, for instance, the largest Libellas, as that at Fig. 5. Pl. 47. are not near so long in copulating or wooing as the small ones; for by the former this act is performed in a very short space, and while they are flying about in the air. Others, of a smaller size, are less quick in this performance; and as we descend to the smallest species, we shall find they take by much the longest time; observing, by the way, that all these slender-bodied ones lay their eggs in the same manner, that is, by fixing them to some substance to which they adhere, till they are ripened into life. My experience well informing me they never scatter them in any loose careless manner as some insects do, but are placed in such proper and apt situations as to receive the influence of the sun to bring them to maturity.

"If we attentively consider these creatures, either in their caterpillar or complete states, we cannot help concluding them to be a rank of beings of greater benefit and advantage to mankind than they appear to be at first view; for, not to mention their being annual 'ministers of nature,' they are appointed by the great Governor of the universe as grand instruments for assisting to preserve that equilibrium so apparently reigning through the insect world, and which all who have made any progress in the study of natural history unanimously confess. Hence the voracious disposition of the Libellas is wisely made to answer a most necessary and beneficial purpose; and the great numbers of small insects which are daily sacrificed to their insatiable appetites, both in their caterpillar as well as complete states, is as strong an instance as any I know of the necessity and propriety of the existence of these animals. The general principle reigning through the whole animal kingdom, of the stronger preying upon the weak and defenceless, can hardly be explained to the purpose of being useful to mankind, and agreeable to the laws of nature, in any one instance more than is evidently to be observed in the subjects I have been describing. The least reflection will confirm this; for if the food of the Libellas when in their complete forms had consisted of the leaves of plants, like the locust genus, and not of those small insects they now prey on; or had it, like the beetle tribe, consisted of the superfluous parts of nature, as the putrid carcases of dead animals, rotten wood, &c. how great a chasm would there have been in the universal chain? how evident and conspicuous would it have appeared? and how could the vast number of small insects, increasing every day during the summer, be restrained and lessened? what genus of the transparent-winged class could possibly have performed this business singly? or could all the genera of flies, and even birds that we know of, have accomplished this end? could all the Dipteræ, or any other {116}kinds that prey on the lesser genera, have prevented such an increase of them as to become in a little time a plague too great to be borne? No. The Almighty Creator has most wisely constituted this genus for executing His commands in the manner I have described; and for this reason they must be considered as beings of greater consequence than the inconsiderate part of mankind allow them to be.

"Nor is this the only advantage arising from their existence. The still waters, where these creatures are inhabitants during their infant state, are in some degree by their assistance preserved sweet and good, that otherwise might corrupt and putrify, for the motion the waters receive by these insects is not trifling; the respiration they perform in that element being observable by a close attention, which, together with that and the motion of thousands of other insects, does in some measure contribute to keep it sweet and wholesome."

PLATE XLVII.

LIBELLULA LYDIA.

Plate XLVII. fig. 4.

ORDER: Neuroptera. SECTION: Subulicornes. FAMILY: Libellulidæ, _Leach_.

GENUS. LIBELLULA, _Linn. &c._

LIBELLULA LYDIA. Subænea, abdomine ([male]) coeruleo lateribus luteis,
alis hyalinis, singulâ strigâ parvâ basali fasciâque latâ transversâ pone
medium, fusco-chalybeis. (Expans. Alar. 2 unc. 9 lin.)

SYN. Libellula Lydia, _Drury, App. vol._ 2.

HABITAT: Virginia.

Front of the head green. Eyes dark brown, very large, and placed near
each other. Thorax green, having on each side two transverse yellow
stripes. Abdomen of the male blue, with small yellow indented marks on
the sides; that of the female yellow; the former having two little horny
substances like tails at the extremity, which are wanting in the female.
Wings reticulated and transparent; the middle of each being of a very
dark blue colour, occupying about a third part, and crossing them from
the anterior to the posterior edges, which by the reflection of white
paper becomes dark brown. A dark brown stripe also, about a quarter of an
inch in length, issues from the base of each wing, almost joining to the
anterior edge; below which the males have a white patch placed on their
inferior wings.

ÆSHNA JUNIA.

Plate XLVII. fig. 5.

ORDER: Neuroptera. SECTION: Subulicornes. FAMILY: Libellulidæ, _Leach_.

GENUS. ÆSHNA, _Fabr._ Libellula, _Linn. &c._

ÆSHNA JUNIA. Fuscescens, unicolor (in vivis virescens?), alis hyalinis,
costâ pallidè infuscatâ, stigmate oblongo, nigro. (Expans. Alar. 4 unc. 3
lin.)

SYN. Libellula Junia, _Drury, App. vol._ 2.

HABITAT: New York.

Head large, and in front of a brown yellow. Eyes brown, almost black,
large, and placed close together. Thorax, when the insect was living,
apparently green. The abdomen is now brown, but {117}was probably green
also; for these kind of insects are very subject to lose the gay colours
they exhibited when alive. Wings reticulated and transparent, appearing
of a brownish colour along the anterior edges; having a small slender
black stripe, about a quarter of an inch long, placed thereon near the
tips, and a small angular white spot at the base of each next the body.

"This insect is very much like one we have in England, but not entirely so, differing in some circumstances from ours; and is introduced rather as a subject for illustrating the history of these insects, than as a specimen meriting a place in this work."--_Drury._

LIBELLULA SERVILIA.

Plate XLVII. fig. 6.

ORDER: Neuroptera. SECTION: Subulicornes. FAMILY: Libellulidæ, _Leach_.

GENUS. LIBELLULA, _Auct._

LIBELLULA SERVILIA. Alis hyalinis, basi flavis, thorace fusco, abdomine
rubro. (Expans. Alar. 2 unc. 9 lin.)

SYN. Libellula Servilia, _Drury, App. vol._ 2. (1773.)

Libellula ferruginata, _Fabr. Mant. Ins._ 336. 11.

Libellula ferruginea, _Fabr. Ent. Syst. t._ 2. _p._ 380.

HABITAT: China.

This insect was of a beautiful red colour when living, but is now much
altered; being considerably darker. Head red brown. Eyes darker, but not
black. Thorax red brown; having a kind of ridge running along the middle
of its upper side. Abdomen red brown, flat underneath, but above
terminating in a high ridge, from the extremity of which a small black
line runs along the upper ridge to the thorax. Wings reticulated and
transparent; having a small, slender, dark stripe placed near the tip of
each, and also near the body a small reddish brown cloud.

PLATE XLVIII.

LIBELLULA CAROLINA.

Plate XLVIII. fig. 1.

ORDER: Neuroptera. SECTION: Subulicornes. FAMILY: Libellulidæ, _Leach_.

GENUS. LIBELLULA, _Auct._

LIBELLULA CAROLINA. Thorace fusco, abdomine ([male]) coeruleo, alis
hyalinis, posticis basi dentato maculâ magnâ ferrugineâ flavo cinctâ.
(Expans. Alar. 3 unc. 9 lin.)

SYN. Libellula Carolina, _Linn. Syst. Nat._ 2. 904. 17. _Amoen. Acad._ 6.
411. 85. _Fabr. Ent. Syst._ 2. 382.

Libellula Chinensis, _De Geer, vol._ 3. _tab._ 26. _f._ 1.

HABITAT: New York, Virginia, China, Madras (_Drury_).

Front of the head dark yellow. Eyes large, and situated near together.
Thorax dirty green. Abdomen round; and in some appears to have been of a
yellow, in others of a blue, colour. Wings reticulated and transparent;
the superior (being narrowest) have only a small dark spot on the
anterior edge of each near the extremity; all the remaining part being
transparent. The inferior have also a small dark spot on each, like the
superior; but close to the abdominal edge they have a large dark
{118}cloud on each, which reaches from the anterior edge almost to the
posterior. At this part the wings are much broader than is generally
observed in any of this genus; gradually widening from the extremity to
the abdominal edge.

AGRION VIRGINICA.

Plate XLVIII. fig. 2.

ORDER: Neuroptera. SECTION: Subulicornes. FAMILY: Libellulidæ, _Leach_.

GENUS. AGRION, _Fabr._ Libellula, _Linn._ Calepteryx, _Leach_.

AGRION VIRGINICA. Aureo-viridis, abdomine nigro, alis fusco-luteis apice
nigricantibus, stigmate ([female]) albo. (Expans. Alar. 2 unc. 9 lin.)

SYN. Libellula virgo var. Gamma, _Drury, App. vol._ 2. (Exclus. Syn.
_Linn._)

HABITAT: Virginia.

Head beautiful golden green. Eyes round, black, not so large as those in
the other figures, and placed at a distance from each other. Thorax
golden green. Abdomen black, long, and slender. Legs black, very spinose.
Wings reticulated, and of a fine shining brown, somewhat inclining to
dark blue, with a remarkable white oval spot near the tips of each, which
part is much darker than the rest; but in the males is the same, the
wings there being of a deep mazarine blue, almost black, and without the
white spots.

Drury observes of this insect, that "it is somewhat like one we have in England, but distinctly different, and soon to be discovered by comparing them together." He nevertheless applied to it the name of the English species, which I have been consequently obliged to reject.

LIBELLULA BERENICE.

Plate XLVIII. fig. 3.

ORDER: Neuroptera. SECTION: Subulicornes. FAMILY: Libellulidæ, _Leach_.

GENUS. AGRION, _Fabr._ Libellula, _Linn._ Calepteryx, _Leach_.

LIBELLULA BERENICE. Lutea, thorace nigro lineato, abdomine ([male])
coeruleo; ([female]) luteo; alis hyalinis nubilâ centrali costali fuscâ
stigmateque nigro. (Expans. Alar. 2 unc. 3 lin.)

SYN. Libellula Berenice, _Drury, App. vol._ 2.

HABITAT: Virginia, New York, Maryland.

Front of the head yellow. Eyes brown, large, and joined close together.
Thorax yellow, and beautifully marked with black stripes, both at top and
on its sides; the former running parallel with it, the other obliquely.
Abdomen yellow, the characteristic of the female; but in the other sex
blue, with black joints. Legs black. Wings transparent, with a slender
black spot near the tips of each; in the middle of each also is a rather
large dark cloud placed on the anterior edge, and another at the base
next the body.

{119}CORDULEGASTER SABINA.

Plate XLVIII. fig. 4.

ORDER: Neuroptera. SECTION: Subulicornes. FAMILY: Libellulidæ, Leach.

GENUS. CORDULEGASTER. _Leach_, _Steph._ Libellula p. _Drury_.

CORDULEGASTER SABINA. Ænea, thorace nigro lineato; abdomine clavato
nigro, flavo annulato, alis hyalinis stigmate minuto. (Expans. Alar. 3
unc. 3 lin.)

SYN. Libellula Sabina, _Drury, App. vol._ 2.

HABITAT: China, and the Island of Johanna, near Madagascar.

Front of the head green. Eyes brown, large, and placed close together.
Thorax green, with three black longitudinal stripes at top, and with
several others running obliquely on its sides. Abdomen, next the thorax,
large and green, with black transverse stripes, but of a sudden becomes
very small and slender for about five-eighths of an inch; black, with
yellow rings; afterwards it becomes broad near the extremity, where it is
black, the apex being yellow. Legs black. Wings transparent, except a
small slender spot near the tips of each on the anterior edges.

LIBELLULA PULCHELLA.

Plate XLVIII. fig. 5.

ORDER: Neuroptera. SECTION: Subulicornes. FAMILY: Libellulidæ, _Leach_.

GENUS. LIBELLULA, _Auct._

LIBELLULA PULCHELLA. Thorace villoso olivaceo, lineolis duabus sub alis,
abdomine ([male]) coeruleo lateribus luteis; alis hyalinis maculâ baseos
fasciâ mediâ apiceque fuscis. (Expans. Alar. 3 unc. 6 lin.)

SYN. Libellula pulchella, _Drury, App. vol._ 2. (1773.)

Libellula bifasciata, _Fabr. Ent. Syst._ 2. 374. (1793.)

HABITAT: New York.

Front of the head green. Eyes brown, large, and placed close together;
behind each are two yellow spots, one round, the other oblong. Thorax
hairy, and of a dirty brownish green; having on the sides two long yellow
spots placed obliquely above one another, the under one being the
shortest. Abdomen flattish, but triangular; in the male blue, but in the
female yellow. Legs black. Wings transparent, with a small brown cloud on
the tip of each; from whence issues along the anterior edge, a slender
black stroke near the middle of each wing. Another small brown cloud
begins on the anterior edge, and reaches about two-thirds cross the wing.
At the base of each, also, a third dark cloud of a longish form seems to
extend from the body near the anterior edge, to almost a third part of
the wing. Between these clouds the males have a remarkable white patch or
spot on each wing, and also another on the abdominal edge of the
posterior ones, all which are not to be discerned in the females.

PLATE XLIX.

LOCUSTA (RUTIDODERES) SQUARROSA.

Plate XLIX. fig. 1.

ORDER: Orthoptera. SECTION: Saltatoria. FAMILY: Locustidæ (Acridites,
Serv.).

GENUS. LOCUSTA. Gryllus; Sect. Locusta, _Linn._ Gryllus, _Fabr._
Acrydium, _Latr._ (SUBGENUS. Rutidoderes, _Westw._ Acrydium, _Serv._ )

LOCUSTA (RUTIDODERES) SQUARROSA. Viridis, pronoto tripartito spinoso,
elytris viridibus fusco-punctatis, alis rubris nigro punctatis. (Expans.
Alar. 4 unc.)

SYN. Gryllus Squarrosus, _Linn. Mant._ 533. _Fabr. Ent. Syst._ 2. 52.

HABITAT: Sierra Leone.

{120}Head green. Eyes perfectly round and dark brown, very prominent, and
standing at a little distance from each other. Antennæ 18-jointed, longer
than the thorax, which is dark green, and on the upper part gibbous;
having on each side three swellings, each of which terminates in three
short and thick spines. Tegmina darkish green, with a great number of
small black spots on them of different shapes. Wings scarlet, spotted
with black; the spots being larger than those of the wing-cases, and of
different shapes. Abdomen green, with several yellow rings surrounding
it, and about the same length as the tegmina. Legs green; the thighs
being armed with spines.

Our author states, that he was informed by a gentleman who lived several years at Sierra Leone, and by whom this species was communicated to him, that "they appear about the end of June, and soon afterwards retire among the branches of the palm trees, where they reside till the violent rains compel them to quit that situation, and live among the plants, &c. on the ground." In the Introduction to the third volume, he however states on the authority of Mr. Smeathman, that "this beautiful locust is an inhabitant of the sandy plains, called Savannas, which indeed abound with palms; but my friend is in doubt whether they have any kind of predilection for those trees.

"'Although the hot climates abound in every part with insects of the locust and cicada kinds, insomuch that their chirping, particularly that of the cicadas, becomes in some instances intolerable; yet in the sandy plains before mentioned, which are thinly covered with grass, their numbers are immensely greater, and of various kinds, sizes, and colours, skipping or flirting about in all directions at every step of the traveller.' Perhaps, indeed, their kinds may not be so various as one would at first imagine, the same insect differing so much from itself in the various periods of its life. From the fact however here mentioned, it seems most certain that these insects breed under ground in Africa, as well as in these climates, according to Linnæus and other entomologists."

From the knowledge which we possess at the present time relative to the economy of this tribe of insects, it is necessary to observe, upon the last above-quoted passage, that the term "breeding under ground," must be restricted to the mere circumstance of the eggs being buried beneath the surface of the earth, because the insects in all their active stages (including that of the pupa) feed upon grass and other vegetable substances above ground.

In following up the very proper plan proposed and partially effected by Mr. Kirby, in the Zoological Journal, of restoring to the primary divisions of the Linnæan genus Gryllus the names which he gave to them, and which have been so confusedly employed by Fabricius and the French entomologists, and of which I have elsewhere given a more complete explanation, it is necessary that the generic name Locusta should be restored to the true migratory locusts composing the genus Acrydium of Latreille, and that a new name (Rutidoderes) should be given to the subgenus Acrydium of Serville, comprising the present and other allied species.

{121}LOCUSTA TARTARICA?

Plate XLIX. fig. 2.

ORDER: Orthoptera. SECTION: Saltatoria. FAMILY: Locustidæ (Acridites,
_Serv._)

GENUS. LOCUSTA. Gryllus; Sect. Locusta, _Linn._ Gryllus, _Fabr._
Acrydium, _Latr._ (SUBGENUS: Locusta. Oedipoda, _Serville_.)

LOCUSTA TARTARICA. Thorace subcarinato tripartito; fusco, lineâ dorsali
pallidâ; elytris fulvescentibus fusco punctatis, alis hyalino
subvirescentibus. (Expans. Alar. 4 unc. 6 lin.)