37S INSECTS OF MASSACHUSETTS. 



suit the articles on the pine and fir saw-flies of Europe, contained 

 in Kollar's " Treatise." 



The following account of a kind of saw-fly which attacks the 

 grape-vine is chiefly extracted from my " Discourse before the 

 Massachusetts Horticultural Society, in 1832," where the in- 

 sect is named Selandria Vitis. The saw-fly of the vine is of a 

 jet-black color, except the upper side of the thorax, which is 

 red, and the fore-legs and under-side of the other legs, which are 

 pale yellow or whitish. The wings are semitransparent, of a 

 smoky color, with dark brown veins. The body of the female 

 measures one quarter of an inch in length, that of the male is 

 somewhat shorter. These flies rise from the ground in the 

 spring, not all at one time, but at irregular intervals, and lay their 

 eggs on the lower side of the terminal leaves of the vine. In 

 the month of July the false caterpillars, hatched from these eggs, 

 may be seen on the leaves, in little swarms, of various ages, some 

 very small, and others fully grown. They feed in company, side 

 by side, beneath the leaves, each swarm or fraternity consisting of 

 a dozen or more individuals, and they preserve their ranks with a 

 surprising degree of regularity. Beginning at the edge they eat 

 the whole of the leaf to the stalk, and then go to another, which 

 in like manner they devour, and thus proceed, from leaf to leaf, 

 down the branch, till they have grown to their full size. They 

 then average five eighths of an inch in length, are somewhat 

 slender and tapering behind, and thickest before the middle. 

 They have twenty-two legs. The head and the tip of the tail 

 are black ; the body, above, is light green, paler before and be- 

 hind, with two transverse rows of minute black points across 

 each ring ; and the lower side of the body is yellowish. After 

 their last moulting they become almost entirely yellow, and then 

 leave the vine, burrow in the ground, and form for themselves 

 small oval cells of earth, which they line with a slight silken film. 

 In about a fortnight after going into the ground, having in the 

 mean time passed through the chrysalis state, they come out of 

 their earthen cells, take wing, pair, and lay their eggs for a sec- 

 ond brood. The young of the second brood are not transformed 

 to flies until the following spring, but remain at rest in their co- 

 coons in the ground through the winter. For some years pre- 



