Page images

so that the beak issues from the under side of the head close to the breast. All the insects included in this division, live on vegetable juices.

I. BUGS. (Hemiptera heteroptera.) The hemipterous insects belonging to this division are various kinds of bugs, properly so called, such as squash-bugs, bed-bugs, fruit-bugs, water-bugs, water-boatmen, and many others, for which there are no common names in our language. In my Catalogue of the Insects of Massachusetts, the scientific names of ninety-five native species are given; but, as the mere description of these insects, unaccompanied by any details respecting their economy and habits, would not interest the majority of readers, and as I am not sufficiently prepared to furnish these details at present, I shall confine my remarks to two or three species only.

The common squash-bug, Coreus tristis, so well known for the injurious effects of its punctures on the leaves of squashes, is one of the most remarkable of these insects. It was first described by De Geer, who gave it the specific name of tristis, from its sober color, which Gmelin unwarrantably changed to mæstus, having, however, the same meaning. Fabricius called it Coreus rugator, the latter word signifying one who wrinkles, which was probably applied to this insect, because its punctures cause the leaves of the squash to become wrinkled. Mr. Say, not being aware that this insect had already been three times named and described, redescribed it under the name of Coreus ordinatus. Of these four names, however, that of tristis, being the first, is the only one which it can retain. Coreus, its generical name, was altered by Fabricius from Coris, a word used by the Greeks for some kind of bug About the last of October squash-bugs desert the plants upon which they have lived during the summer, and conceal themselves in crevices of walls and fences, and other places of security, where they pass the winter in a torpid state. On the return of warm weather, they issue from their winter quarters, and when the vines of the squash have put forth a few rough leaves, the bugs meet beneath their shelter, pair, and

immediately afterwards begin to lay their eggs. This usually happens about the last of June or beginning of July, at which time, by carefully examining the vines, we shall find the insects on the ground or on the stems of the vines, close to the ground, from which they are hardly to be distinguished on account of their dusky color. This is the place where they generally remain during the daytime, apparently to escape observation; but at night they leave the ground, get beneath the leaves, and lay their eggs in little patches, fastening them with a gummy substance to the under sides of the leaves. The eggs are round, and flattened on two sides, and are soon hatched. The young bugs are proportionally shorter and more rounded than the perfect insects, are of a pale ash-color, and have quite large antennæ, the joints of which are somewhat flattened. As they grow older and increase in size, after moulting their skins a few times, they become more oval in form, and the under side of their bodies gradually acquires a dull ochreyellow color. They live together at first in little swarms or families beneath the leaves upon which they were hatched, and which, in consequence of the numerous punctures of the insects, and the quantity of sap imbibed by them, soon wither, and eventually become brown, dry, and wrinkled; when the insects leave them for fresh leaves, which they exhaust in the same way. As the eggs are not all laid at one time, so the bugs are hatched in successive broods, and consequently will be found in various stages of growth through the summer. They, however, attain their full size, pass through their last transformation, and appear in their perfect state, or furnished with wing-covers and wings, during the months of September and October. In this last state the squash-bug measures six tenths of an inch in length. It is of a rusty black color above, and of a dirty ochre-yellow color beneath, and the sharp lateral edges of the abdomen, which project beyond the closed wingcovers, are spotted with ochre-yellow. The thin overlapping portion of the wing-covers is black; the wings are transparent, but are dusky at their tips; and the upper side of the abdomen, upon which the wings rest when not in use, is of a deep black color, and velvety appearance. The ground-color of this insect is really ochre-yellow, and the rusty black hue of the head, thorax, thick part of the wing-covers, and legs, is occasioned by numerous black punctures, that, on the head, are arranged in two broad black longitudinal lines, between which, as well as on the margin of the thorax, the yellow is distinctly to be seen. On the back part of the head of this bug, and rather behind the eyes, are two little glassy elevated spots, which are called eyelets, and which are supposed to enable the insect to see distant objects above it, while the larger eyes at the sides of the head are for nearer objects around it. Eyelets are also to be found in grasshoppers, locusts, and many other insects. In some of our species of Coreus there is a little thorn at the base of the antennæ, the legs are also thorny on the under side, and the hindmost thighs are much thicker than the others; but none of these characters are found in squash-bugs.* When handled, and still more when crushed, the latter give out an odor precisely similar to that of an overripe pear, but far too powerful to be agreeable.

In order to prevent the ravages of these insects, they should be sought and killed when they are about to lay their eggs; and if any escape our observation at this time, their eggs may be easily found and crushed. With this view the squash-vines must be visited daily, during the early part of their growth, and must be carefully examined for the bugs and their eggs. A very short time spent in this way every day, in the proper season, will save a great deal of vexation and disappointment afterwards. If this precaution be neglected or deferred till the vines have begun to spread, it will be exceedingly difficult to exterminate the insects, on account of their numbers; and, if at this time dry weather should prevail, the vines will suffer so much from the bugs and drought together, as to produce but little if any fruit. Whatever contributes to bring forward the plants rapidly, and to promote the vigor and luxuriance of their foliage, renders them less liable to suffer by the exhausting punctures of the young bugs. Water drained from a cow

They appear to belong to the genus Gonocerus of Burmeister.

yard, and similar preparations, have, with this intent, been applied with benefit.

The wheat-fields and corn-fields of the South and West often suffer severely from the depredations of certain minute bugs, long known there by the name of chinch-bugs, which fortunately have not yet been observed in New England.* It is not improbable, however, that they may spread in this direction, and attack our growing grain and other crops. In anticipation of such a sad event, and to gratify a curiosity that has been expressed concerning these offensive insects, I venture to offer a few remarks upon them. Attention seems early to have been directed to them. They are mentioned in the eleventh volume of Young's “ Annals of Agriculture," published, I believe, about 1788. From this work Messrs. Kirby and Spence probably obtained the following account, contained in the first volume of their interesting “ Introduction to Entomology.” “ America suffers in its wheat and maize from the attack of an insect, which, for what reason I know not, is called the chinch-bug fly. It appears to be apterous, and is said in scent and color to resemble the bed-bug. They travel in immense columns from field to field, like locusts, destroying everything as they proceed; but their injuries are confined to the States south of the 40th degree of north latitude. From this account,” add Kirby and Spence, “the depredator here noticed should belong to the tribe Geocorisa, Latr.; but it seems very difficult to conceive how an insect that lives by suction, and has no mandibles, could destroy these plants so totally.” I have ascertained, from an examination of living specimens, that the chinch-bug is the Lygaus leucopterus, or white-winged Lygæus, described by Mr. Say, in December, 1831, in a rare little pamphlet on the “Heteropterous Hemiptera of North America.” It appears, moreover, to belong to the modern genus Rhyparochromus. In its perfect state it is not apterous, but is provided with wings, and then measures about three twentieths of an inch in length. It is readily distinguished by its white wing-covers, upon each of which there is a short central line and a large marginal oval spot of a black color. The rest of the body is black and downy, except the beak, the legs, the antennæ at base, and the hinder edge of the thorax, which are reddish yellow, and the fore part of the thorax, which has a grayish lustre. The young and wingless individuals are at first bright red, changing with age to brown and black, and are always marked with a white band across the back. It is a mistake that these insects are confined to the States south of the 40th degree; for I have been favored with them by Professor Lathrop, of Beloit College, Wisconsin, and by Dr. Le Baron, of Geneva, Illinois. The latter gentleman had no difficulty in obtaining a sufficient number without going out of his own garden. The eggs of the chinch-bug are laid in the ground, in which the young have been found, in great abundance, at the depth of an inch or more. They make their appearance on wheat about the middle of June, and may be seen in their various stages of growth on all kinds of grain, on corn, and on herds-grass, during the whole summer. Some of them continue alive through the winter in their places of concealment. A very good account of these destructive bugs, with an enlarged figure, will be found in the “ Prairie Farmer," for December, 1845. In the same publication, for September, 1850, there is an excellent description of the chinch-bug, by Dr. Le Baron, who, not being aware that it had been previously named by Mr. Say, called it Rhyparochromus devastator.

* While this sheet is passing through the press, I have to record the discovery of one of these bugs in my own garden, on the 17th of June, 1852.

During the summer of 1838, and particularly in the early part of the season, which, it will be recollected, was very dry, our gardens and fields swarmed with immense numbers of little bugs, that attacked almost all kinds of herbaceous plants. My attention was first drawn to them in consequence of the injury sustained by a few dahlias, marigolds, asters, and balsams, with which I had stocked a little border around my house. In the garden of my friends the Messrs. Hovey, at Cambridgeport, I observed, about the same time, that these insects were committing sad havoc, and was informed that various means

« PreviousContinue »