226 INSECTS INJURIOUS TO VEGETATION. 



in form, and in their transformations. The caterpillars of the 

 Sphinges have sixteen legs, placed in pairs beneath the first, 

 second, third, sixth, seventh, eighth, ninth, and last segments of 

 the body ; all of them, except the ^gerians and Glaucopidians, 

 have either a kind of horn or a tubercle on the top of the last seg- 

 ment, aiid, when at rest, sit with the forepart of the body elevated. 



Having devoted a large portion of this treatise to a descrip- 

 tion of the spinning moths, my observatiofis on the other insects 

 -of this order must be brief, and confined to a few species, which 

 are more particularly obnoxious on account of their devasta- 

 tions in the caterpillar state. Those persons, who are curious 

 to know more about the Sphinges than can be included in this es- 

 say, are referred to my descriptive catalogue of these insects, 

 contained in the thirty-sixth volume of Professor Silliman's 

 " Journal of Science." 



Every farmer's boy knows the potato-worm, as it is commonly 

 called ; a large green caterpillar, with a kind of thorn upon the 

 tail, and oblique whitish stripes on the sides of the body. This 

 insect, which devours the leaves of the potato, often to the great 

 injury of the plant, grows to the thickness of the fore-finger, and 

 the length of three inches or more. It attains its full size from 

 the middle of August to the first of September, then crawls down 

 the stem of the plant and buries itself in the ground. Here, in a 

 few days, it throws off its caterpillar-skin, and becomes a chrysa- 

 lis, of a bright brown color, with a long and slender tongue-case, 

 bent over from the head, so as to touch the breast only at the end, 

 and somewhat resembling the handle of a pitcher. It remains 

 in the ground through the winter, below the reach of frost, and in 

 the following summer the chrysalis-skin bursts open, a large 

 moth crawls out of it, comes to the surface of the ground, and 

 mounting upon some neighbouring plant, waits till the approach 

 of evening invites it to expand its untried wings and fly in search 

 of food. This large insect has generally been confounded with 

 the Carolina Sphinx, {Sphinx Carolina of Linnaeus), which it 

 closely resembles. It measures across the wings about five 

 inches ; is of a gray color, variegated with blackish lines and 

 bands ; and on each side of the body there are five round, orange- 

 colored spots encircled with black. Hence it is called by English 



