« PreviousContinue »
it is evident that they are much too large for any of the parasitical insects which attack the larvæ and eggs of the Hessian and wheat flies; and they appear sometimes to have been mistaken for the latter. In an extract from a paper by Mr. Worth, on the Hessian fly, mention is made of a pale yellow worm (maggot), about three sixteenths of an inch long, having been found by him within the stalks of wheat near the root, where its presence was detected by a swelling of the part attacked. This was perhaps the larva of one of the Oscinians.
A careful examination of all the insects that inhabit our fields of grain is very much wanted.
The various insects, improperly called bot-bees, are twowinged flies, and belong to the order Diptera, and the family Estride, so named from the principal genus in it. Bot-fies do not seem to have any mouth or proboscis; for although these parts do really exist in them, the opening of the mouth is extremely small, and the proboscis is very short, and is entirely concealed in it; so that these insects, while in the winged state, do not appear to be able to take any nourishment. They somewhat resemble the Syrphians in form and color, and in the large size of their heads; but the eyes are proportionally small, and there is a large space between them. The face is swollen or puffed out before. The antennæ are very short, and almost buried in two little holes, close together, on the forehead. The winglets are large and entirely cover the poisers. The hind body of the females ends with a conical tube, bent under the body, and used for depositing the eggs, which the insect lays whilst flying. The larvæ or young of bot-flies live in various parts of the bodies of animals. They are thick, fleshy, whitish maggots, without feet, tapering towards the head, which is generally armed with two hooks; and the rings of the body are surrounded with rows of smaller hooks or prickles. When they are fully grown, they drop to the ground and burrow in it a short distance. After this, the skin of the maggot becomes a hard and brownish shell, within which the insect turns to a pupa, and finally to a fly, and comes out by pushing off a little piece like a lid from the small end of the shell.
More than twenty different kinds of bot-flies are already known, and several of them are found in this country. Some of them have been brought here with our domesticated animals from abroad, and have here multiplied and increased. Three of them attack the horse. The large bot-fly of the horse (Gasterophilus equi) has spotted wings. She lays her eggs about his knees; the small red-tailed species (G. hæmorrhoidalis), on his lips; and the brown farrier bot-fly (G. veterinus) under his throat, according to Dr. Roland Green. By rubbing and biting the parts where the eggs are laid, the horse gets the maggots into his mouth, and swallows them with his food. The insects then fasten themselves, in clusters, to the inside of his stomach, and live there till they are fully grown. The following are stated to be the symptoms shown by the horse when he is much infested by these insects. He loses flesh, coughs, eats sparingly, and bites his sides; at length he has a discharge from his nose, and these symptoms are followed by a stiffness of his legs and neck, staggering, difficulty in breathing, convulsions, and death. No sure and safe remedy has yet been found sufficient to remove bots from the stomach of the horse. The only treatment to be recommended, is copious bleeding, and a free use of mild oils, in the early stages of the attack. The preventive means are very simple, consisting only in scraping off the eggs or nits of the fly every day.* Bracy Clark, Esq., who has published some very interesting remarks f on the bots of horses and of other animals, maintains that bots are rather beneficial than injurious to the animals they infest. His principal work on this subject I have not yet seen. The maggots of the Estrus bovis, or ox bot-fly, live in large open boils, sometimes called wornils or wurmals, that is, worm-holes, on the backs of cattle. The fly is rather smaller than the horse
See Dr. Green's “Natural History of the Horse-Bee," in Adams's “ Medical and Agricultural Register,” Vol. I., p. 53; and the same in "The New Eng. land Farmer," Vol. IV., p. 345.
† “Observations on the genus Estrus,” in the “Transactions of the Linnæan Society," Vol. III., p. 289, with figures ; “On the insect called Oistros by the Ancients,” in Vol. XV. of the same work; and “ An Essay on the Bots of Horses and other Animals.” 1 vol. 4to. Lond. 1815.
bot-fly, although it comes from a much larger maggot. The sheep bot-fly (Cephalemyia ovis) lays its eggs in the nostrils of sheep, and the maggots crawl from thence into the hollows in the bones of the forehead. Deer are also afflicted by bots peculiar to them. Our native hare, or rabbit, as it is commonly called, sometimes has very large bots, which live under the skin of his back. The fly (Estrus buccatus) is as big as our largest humble-bee, but is not hairy. It is of a reddish black color; the face and the sides of the hind body are covered with a bluish white bloom; there are many small black dots on the latter, and six or eight on the face. This fly measures seven eighths of an inch, or more in length, and its wings expand about three quarters of an inch. It is rarely seen; and my only specimen was taken in the month of July, many years ago.
At the very end of this order is to be placed a remarkable group of insects, which seems to connect the flies with the true ticks and spiders. Some of these insects have wings; but others have neither wings nor poisers. Of the winged kinds there is one (Hippobosca equina) that nestles in the hair of the horse; others are bird-flies (Ornithomyia), and live in the plumage of almost all kinds of birds. The wingless kinds have sometimes been called spider-flies, from their shape; such are sheep-ticks (Mellophagus ovis), and bat-ticks (Nycteribia). These singular creatures are not produced from eggs, in the usual way among insects, but are brought forth in the pupa state, enclosed in the egg-shaped skin of the larva, which is nearly as large as the body of the parent insect. This egg-like body is soft and white at first, but soon becomes hard and brown. It is notched at one end, and out of this notched part the inclosed insect makes its way, when it arrives at maturity.
The flea (Pulex), may almost be considered as a wingless kind of fly. Its proboscis seems to be intermediate in its formation between that of fies and of bugs; its antennæ are concealed in holes in the sides of its head, like those of certain water-bugs (Nepa and Belostoma), and somewhat resemble them in shape; while the transformations of the flea are not very much unlike those of the flies, whose maggots cast off their skins on becoming pupæ.
Having now arrived at the end of my work, I have only to add a few remarks by way of conclusion. It has been my design to present to the reader a sketch of the scientific arrangement of the principal insects which are injurious to vegetation, not only in New England, but in most of the United States. The descriptions of the insects, being drawn up in familiar language, will enable him to recognize them, when seen abroad, in all their forms and disguises. The hints and practical details, scattered throughout the work, it is hoped will serve as a guide to the selection and the application of the proper remedies for the depredations of the insects described. I regret that it has not been in my power to do full justice to this important subject, which is far from having been exhausted. My object, however, will have been fully attained, if this treatise, notwithstanding its many faults and imperfections, should be found to afford any facilities for the study of our native insects, and should lead to the discovery and the general adoption of efficient means for checking their ravages.
134 Angoumois grain-moth, 387, 392
162 Anthomyians (Anthomyiadæ), 493
207, 209, 405, 406
253 Ants attend plant-lice, 207, 209
371 Aphidians (Aphidida), 177, 201
bud-moths, . 375, 377
342 Apple-trees injured by American
bark-lice, 220, 222
canker-worms, 361, 369
caterpillars, 274, 282,
286, 292, 294, 299, 328, 331
260, 403 Apple-trees, other insects at-