98 DR. HARRIS'S REPORT. April, 



of the body project at the sides, being there surmounted with minute 

 tubercles. The pu|)a state takes place in the leaf, and continues 

 about one weei<, when the perfect insect bursts from its confinement 

 and escapes into the air. 



Hispa rosea devours the tender leaves of the apple tree, and its 

 larvae are found also in the leaves of that tree in July. Hispa sutu- 

 ralis attacks the leaves of the Robinia pseudacacia, or locust. 



The genus Cassida is distinguished for its shield-shaped body, 

 whence it derives its name. The head is covered by the semicircu- 

 lar thorax ; the antennae are about the length of the thorax ; the body 

 is convex above and flat beneath. The larvae live on the leaves of 

 plants. They have three pairs of legs ; their body is oval, and flat- 

 tened, or but slightly convex above, and armed at the sides with 

 spines, and the tail is terminated by two considerably longer than the 

 rest, forming a kind of fork. This fork serves to retain the excre- 

 ment when voided, and a mass is often thus accumulated which 

 equals half the body in magnitude. The tail, with the loaded fork, 

 is recurved over the back, and thus protects the insect from the sun, 

 and probably also from its. enemies. When the pupa state approach- 

 es, the larva fixes the hinder part of its body firmly to the leaf, the 

 skin over the anterior extremity is longitudinally rent, and is grad- 

 ually slipped backwards. The pupa has some spines near the tail 

 which secure it to the cast-skin ; its body also is furnished with four 

 long teeth-like projections on each side. The pupa state continues 

 only a few days. 



Cassida aurichalcea appears to be appropriated to different spe- 

 cies of Convolvulus, though it is occasionally found on Solatium 

 dulcamara ; it occurs in great abundance on the Convolvulus sept- 

 um, and on the sweet potato-vine. The leaves of these plants are 

 devoured both by the larvae and perfect insects. The latter appear 

 first during the months of May and June, having probably survived 

 the winter in the perfect state, in some place of concealment. The 

 first brood of larvae arrive at their growth and are metamorphosed 

 into pupae, and subsequently into perfect insects, early in July, when 

 a second brood is produced, from which proceed the insects found 

 in spring. In June, 1824, Mr. Lowell sent me specimens of this 

 little beetle, which he found to be injurious to the sweet potato-vine, 



