(59) Scirpus simplex. Stem triangular; Spikes with the aspect of S. tuberculatus; Seed longitudinally striate and regularly punctate between the ridges, presenting a beautiful appearance under a lens. Bristles 6.

ART. IX.-UPON THE ECONOMY OF SOME AMERICAN SPECIES OF HISPA. By T. W. HARRIS, M. D. Read Feb. 18, 1835.

It is the peculiar province of the naturalist to investigate the habits and economy of animals. The discovery of these does infinitely more towards the advancement of a science founded wholly upon observation, than the mere description of new species. This is more especially true in entomology, in which, such has been the cupidity and vanity of collectors, that the legitimate objects of the science, the habits, uses, and stations of insects in the system of nature, have been neglected for the acquisition and description of species, the indication of new genera, and the coining of an immense number of new and pedantic terms, in a science whose nomenclature is already overburdened. If the foregoing remarks be founded in fact, no apology will be necessary for the appearance of the present paper in the pages of this journal.

Hitherto the larva and pupa of HISPA, and their manner of living, have been unknown; after they have been described, it will remain for the makers of systems to assign to this genus of insects its proper place.

Mr. Kirby, in treating of that fanciful theory abounding in hard names, the supposed analogy or correspondence between the forms of larvæ and those of other aniVOL. I.-PART II.

19

mals, says that "Cassida seems to belong to a peculiar type;" that "at present he knows of no analogous form amongst the apterous tribes, and must therefore leave this without a denomination;" and that "perhaps the larva of Hispa or Alurnus, when known, will throw light upon this subject." The larva of Hispa has not the most distant resemblance to that of Cassida, or to any other now known among the genera with which it has been artificially associated. So far as mere form is concerned, it is related to the wood-eating larvæ of the Capricorn beetles, particularly of the genus Callidium; while its habits are those of the leaf-mining caterpillars of certain moths.

Towards the end of July, 1820, I perceived upon an apple-tree several leaves which had large brownish spots upon them. These spots were not occasioned by disease, but by the destruction of the internal pulpy substance or parenchyma of the leaf, while the cuticle or skin, both above and below, remained entire. When a leaf was held between the eye and the light, there could be seen, through the discolored but semi-transparent cuticle, a little whitish flattened grub, which had devoured the parenchyma, and lay enclosed in the cavity thus formed between the two layers of skin. On being disturbed, this insect moved with a wriggling motion from one part of its retreat to another, backwards quite as readily as forwards. The shape of the spots was irregular, and they varied somewhat in size; but on an average each one might have been about an inch square. Several leaves containing larvæ, among which was one that had already passed into the pupa or chrysalis state, were shut

*

Kirby & Spence, Introduction to Entomology, III. p. 168.

up in a box. Soon afterwards the insects passed through their transformation, and, leaving the cast-off pupa-skin nearly entire within the cavities which they had occupied, they made irregular perforations through the dried cuticle and came out upon the surface of the leaves. The insects, thus disclosed in the perfect or winged state, proved to be little beetles belonging to the genus Hispa; but as they were subsequently lost, it is not in my power positively to identify them with any of the species now in my collection.

[Fig.1.]

In June, 1827, I discovered a leaf of the poplar-tree which contained a small dead larva very closely resembling that of the Hispa of the apple-tree; but it was not till the 17th of July, 1829, that an opportunity of observing in detail the habits of these insects again presented itself. Upon this day I found larvæ, like those of the apple-tree, feeding, in the same manner, upon the parenchyma of the leaves of the white oak. Each one of these insects, when fully grown, measured from 20 to 27 hundredths of an inch in length. [Fig. 1.] The head was horny and of a brownish black color; the body, consisting of 11 segments, flattened and broad near the head, gradually narrower behind, was yellowish white, except the greater part of the upper side of the first segment, a spot in the middle of the under side of the same, and the upper part of the tip of the last segment, which were dark brown or nearly black. The head was small in proportion to the size of the first segment, and partially drawn within it. Minute antennæ were perceptible, and the jaws were short, strong, somewhat triangular, and simple, or scarcely in

I

dented within. The legs were six, short, and of a brown color, a pair beneath the first, second, and third segments. The other segments were dilated at the sides, and terminated by small brown tubercles. Above these lateral mammillary projections was a series of 7 smaller ones, each bearing a spiracle or aperture for respiration. The second segment, at the sides, near its anterior edge, was furnished with two larger spiracles, and two, still larger, were situated upon the upper part of the terminal segment, near its tip. The fourth and remaining segments, except the last, had, both above and below, a transverse callous spot, covered with minute projections like a rasp, which appeared to be designed to aid the insect in its

motions.

On the fifth of August five of these larvæ were transformed to pupa, four of which assumed the perfect state on the eleventh, and the fifth on the twelfth of the same month; from which it appears that the pupa state lasts only between six and seven days.

The color of the pupa was of a yellowish white, but, as it approached the period of its final change, the body became reddish, and the wing-sheaths brown. Its body was rather shorter and broader than that of the larva ; the abdominal segments were tuberculated at the sides, and were furnished, both above and beneath, in the centre of each segment, with a transverse series of elevations, much larger and more prominent than those of the larva, and tipped with short bristles. The sheaths of the wings and legs were folded on the breast, and those of the antennæ under the lateral margins of the first and second segments. When disturbed, the pupa moved about in its habitation, by means of the rasps upon its body which served instead of feet.

This insect, in its perfect form, resembles HISPA ròsea

of Weber in sculpture, size, and shape, and indeed offers no character by which it may be distinguished from that common insect, except its dull yellow colour, and the much deeper crimson tint of the lines with which it is adorned: possibly it is merely a variety arising from a difference of food, or from other causes of an accidental nature. The habitat of the larva of the rosea is, as yet, unknown to me; in its winged state it occurs in abundance, during the latter part of May and beginning of June, upon the young leaves of ARONIA arbutifolia.

Mr. Say has re-described the HISPA rosea of Weber under the name of marginata, and it is highly probable that the HISPA quadrata of Fabricius is also identical. Weber's specific name, however, having the priority, in point of time, both over that of Fabricius and of Say, must be retained. Fabricius has erroneously cited the rosea of Weber as synonymous with his HISPA suturàlis.

The following descriptions will serve to point out the difference between HISPA rosea and the variety (if it be such) which inhabits the oak.

HISPA rosea. Fulvous red, lineated with blood red: elytra truncated, sulcated, and punctured in double rows; breast and belly black; feet testaceous.

Length from twenty to twenty-five hundredths of an

inch.

Antennæ brownish, paler at tip. Thorax covered with close and deep punctures; anterior and lateral edges blood red, and two very faint reddish lines on the disk. The coleoptra form an oblong square, of a fine fulvous red colour, darker toward the tip, serrated on the outer edge, which, with the suture, is elevated. Four elevated lines on each elytron, the first one, next the suture, forked at the base, and the third interrupted in the middle. These ridges and the margin are ornamented with dark purplish