Among the leaf-beetles that are injurious to vegetation are those belonging to the tribe called 

 HisPAD.'K. Such are the little insects which you lately sent me, which you found to have destroyed 

 the foliage of the Basswood, or American Linden [Tilia Americana), in Jefferson county, N. Y. A 

 variety of the same insect attacks tiie leaves of the White Oak, and occasionally those of the Apple 

 tree, also. These leaf-beetles are described in the second edition of my Ti'eatisc, pp. 105 to 107 ; 

 and a more full account of them, with figures of the grub and chrysalis, will be found in the first 

 volume of the Bostoii Journal of Natural History, pp. 141 to 151. 



The day before your letter came to hand, I found one of these beetles, which had just emerged 

 from a leaf of the Linden, and I saw several other leaves on the same tree that had been eaten by 

 insects of this kind. In the summer of 1851 the White Oaks in some parts of Long Island suffered 

 very much from their attacks; and, witii this commTinication, you will receive one of the leaves, 

 showing in what way and to what extent they were affected.* 



Your insect is the Rosy Ilispa, or Hispa rosece, of Weber, otherwise called Hispa qiiadrata by 

 Fabricuis, and Hispa marginata by Say. The accompanying rude and very magnified sketch will 

 give an idea of the form of this pretty leaf-beetle, and the line at the side 

 of it indicates its natural size, which rarely exceeds one-fifth of an inch in 

 length. Its body is light red above, ornamented with short blood-red lines, 

 and is mostly blackish beneath. The antennae are black, and the legs are 

 reddish-yellow. Tlie thorax is rough with small indentations, or punctures, 

 as they are called; the wing-covers are notched around the outer edges, 

 have raised I'ibs upon them, and deep punctures in the intervals. The 

 Rosy Hispa may be found abundantly in May and June on the leaves of the 

 Shad-bush, or Amelanchier Canadem^is, and on other shrubs of the same 

 family, the leaves of which it devours. The variety which inhabits the Oak 

 differs iu being of a reddish yellow color, ornamented with blackish-red 

 lines. This difference may be occasioned by its food, or by other causes of 

 an accidental nature. 



The'female Hispa deposits her eggs, for the most part, singly, on the upper 

 surface of the leaves. These eggs are glued fast to the leaves, and are covered with rough, blackish 

 crust. The grubs, hatched from the eggs, immediately penetrate into the pulpy substance of the 

 leaf, which they devour, leaving the cuticle, or skin of the leaf, both above and beneath, untouched. 

 The part of the leaf thus, as it were, undermined, becomes dry and brown, and through the semi- 

 transparent cuticle, when held between the eye and the light, the grub may be seen in its burrow. 

 The grub comes to its growth toward the end of July, and then measures from one-fifth to one- 

 quarter of an inch in length. It is somewhat flattened, and tapers toward the hinder extremity. 

 Its color is yellowish- white, except the head, the first segment, and the tail, which are blackish. _ It 

 has six legs, a pair beneath the first, second, and third segments ; and on each of the remaining 

 segments, both above and beneath, except the last, there is a transverse horny spot, which is rough, 

 like a rasp. The sides of these segments, also, are prominent, and are surmounted each witha 

 little brownish tubercle, or wart. Early in August the grub is transformed to a chrysalis within 

 its retreat. The chrysalis, which ia whitish at first, finally becomes brown. Like the grub, the 

 sides of its body are prominent, and there are transverse rasps on the back and belly. In about one 

 week afterward the insect easts off its pupa skin, and comes out a fully formed beetle, which haa 

 only to force a pasjftge through the thin cuticle of the leaf in order to escape into the open air. 

 The insect probably passes the winter in the beetle form in some place of concealment. Such is 

 briefly a history of the transformations of this little Hispa. 



The caterpillars, which, together with their cocoons, you sent to me, with the information that 

 they were very destructive to the Arbor Vitic, Cedar, and other resinous plants in Tennessee, are 

 drop-worms, or basket-worms, referred to on page 319 of my Treatise. To their destructive powers 

 I can testify from my own sorrowful experience ; a fine Arbor Vita; tree, on which I had placed, in 

 May, 1850, some of the cocoons received during the pi'evious autumn from Philadelphia, not having 

 yet recovered from the effects of the ravages of the insects, though the latter were limited to one 

 summer. These drop-worms are exceedingly curious and interesting in all their habits and trans- 

 formations, the history of which might form the subject of a long memoir. But neither time nor 

 space will permit me to off'er any more than a very short sketch of their history, whiehis drawn 

 up from notes written in the years 1849 and 1850, when I had a colony of the living insects in 



These' insects inhabit the Swamp Cedar {Cupressus Thyoides), Arbor Vitre {Thuya occidentalis), 

 'L^vqYi {Larix Americana), and Hemlock (^ifes Canadensis), with other resinous trees; but occa- 

 sionally they attack the Linden, the Maple, and even fruit trees. They are common in the Middle 

 and Southern States, and probal)ly most of the Western States also ; but hitherto they have not 

 been discovered in New England. They belong to Mr. Guilding's American genus Otketicus ; and, 

 as they do not seem to have received a scientific name, I shall venture to give them that of OikcH- 

 cus coniferarum, from their preference to the trees of the cone-bearing tribe. The species is probably 

 the same as the one noticed by my lamented friend, the late Mr. Edward Doubledat, m Newmans 

 Entomologist, No. 7, pp. 97-98 ; but the male insect does not agree with the figure, copied from one 



* Quite similar to the manner in which the Basswood leaves are eaten.— Ed. 



