ASH SAW-FLIES. 545 



like elevation, and if cut out of tbeir covering? are found to be very 

 soft, the outer membrane being exceedingly delicate and easily ruptured. 

 The larvae are evidently hatched within two or three days after the eggs 

 are deposited, and are at first slender, whitish worms, with black heads 

 and thoracic legs. They crawl at once to the leaflets and appear to se- 

 lect the more tender ones for the commencement of their work. They 

 grow quite rapidly and reach the first molt on the third or fourth day. 

 They are mostly found adhering to the under surface of the leaves and 

 forming a coil, though sometimes extended, especially when feeding, 

 and as they eat away the entire leaf, cutting away at the edges or at 

 the holes entirely through the leaf, they eat any poisonous substance 

 sprinkled or dusted on the upper surface. When young they usually 

 keep pretty well clustered together or on the same leaf, but afterwards 

 scatter quite generally, the early clustering being due no doubt to the 

 eggs being laid near together and on the same leaf. The worms molt 

 at least three or four times before reaching maturity. They leave the 

 trees before pupating, which is probably done under ground, pass- 

 ing the winter in the pupa condition. The fly has been observed 

 in abundance from Aj^ril 15 until June. Tachina and Ichneumon flies 

 prey upon the false-caterpillars. 



Larva. — Head polished jet-black, as are the thoracic legs, otherwise the body is 

 clear green, with a slightly darker dorsal line. Eight pairs of abdominal legs. The 

 skin somewhat wrinkled, but neither hairy nor slimy. (Osborn.) 



Saw-fly. — Body black throughout, except the upper part of the thorax, which is 

 honey-yellow or sometimes orange or reddish, the amount, as well as the shade, dif- 

 fering somewhat in different individuals. The males are more slender and shorter 

 than the females. In some specimens the front legs are partially yellowish. (Os- 

 born, Bull. Iowa Ag. College, 1884, p. 80.) 



11. Selandria sp. 



Miss Murtfelit describes, in a report to the Agricultural Department, 

 a saw-fly larva which seems to differ from the preceding species in 

 having a double row of short black spines on each segment. She re- 

 fers to them as follows : 



Early in the summer the foliage of the ash trees {Fraxinus amefricana) was much 

 eaten by a Tenthredinid that I have not yet been able to rear, although I have ob- 

 served it for several successive years. The slug is about the size of, and very similar 

 in appearance to, Selandria vitis, being pale-green, with small, immaculate black 

 head and a double transverse row of short black spines on each segment. It inhabits 

 the under surfaces of the leaves, and in feeding perforates them with round holes, of 

 sizes corresponding with its stage of growth. It enters the ground about the last of 

 May and incloses itself in a frail earthen cell. It seems to be but single-brooded, 

 and in the rearing-cage either dries up or molds, without chauging to pupa, in the 

 course of the summer. 



12. Selandria? larva, Xo. 1. 



This and the following saw-fly larvae occurred frequently on young 

 ash shrubs at Rangeley Lake. They resemble the larvae of Nematus, 

 but differ in having eight instead of seven pairs of abdominal legs. 

 5 ENT 35 



