go An Insect Destructive to Squash - Viiies. 



AN INSECT DESTRUCTIVE TO SQUASH -VINES. 



During the month of August, the leaves of our squash-vines often pre- 

 sent a riddled appearance, disclosing the presence of an enemy. If we 

 examine the edges of the holes, we shall find the plump, rounded larva of 

 a beetle, feeding sometimes on the upper, though generally upon the under 

 surface of the leaf It belongs to the family of Coccincllidce, or lady-bugs ; 

 and although, as a general rule, the species of this group are of 

 positive benefit to vegetation in destroying large numbers of plant- 

 lice which blight our fruit and shade trees, a few are herbivorous in 

 nature, and among them the insects of which we are speaking. In the larval 

 state, during which they inflict almost all the injuries of which they are capa- 

 ble, they are of a bright-yellow color, covered above with long, branching, 

 black thorns, sometimes tipped.with white, and arranged in six longitudinal 

 rows. The space between the two middle rows is widened anteriorly by the 

 more lateral insertion of the three first spines. Behind the thorns of the 

 first segment, there is a transverse row of short, fine, black-tipped hairs. 

 The head, the legs, and the under side of the abdomen, are covered with 

 short, fine hairs ; the tips of the legs are black. When fully grown, the 

 larvae are about three-eighths of an inch in length by a little less than half an 

 inch in breadth. They crawl but sluggishly, using their terminal segment 

 as an additional leg ; and live in large numbers on the squash-vines, where 

 their voracity is attested by the rapidity with which their cast-off skins 

 increase in size and number. These skins are white, transparent pellicles, 

 covered with characteristic thorns, and preserving in some measure the 

 shape of their former inhabitants. 



Toward the latter part of August, or the first of September, the larvae 

 are fully grown, and begin to change to their pupal state : they stop eating, 

 and crawl to a suitable place, generally upon the top of a leaf, where they 

 can fasten themselves by their terminal segments to one of the veins ; then 

 slough their skin, and appear as pupae. 



The pupa is of the same general color as the larva : the eyes are dusky, 

 and the stumpy feet crowded together on the breast. The whole body, 

 but more especially the head, thorax, and appendages, is covered with 



