422 NEW YORK STATE MUSEUM 



of worms when in this posture. " The larvae appear to attain their full 

 size in about 5 to 7 days after hatching, certainly not more than 10 days." 

 There appear to be three molts. On gaining maturity, the larvae descend 

 from the tree and spin oval elongated cocoons beneath the moss or other 

 convenient shelter, where they remain unchanged during the winter, trans- 

 forming to the pupa the next spring. The following characterization of 

 the different stages is taken from Dr Packard's descriptions. 



The egg is slender, cylindrical, tapering towards each end, slightly 

 over ','25 of an inch in length. 



The very young larvae have dusky or smoky green heads, and uniform 

 pea-green bodies. After the first molt, the body is a pale green and 

 without the glaucous pearly bloom of the latter two stages. The head and 

 thoracic feet are black and the segments wrinkled as in the adult. 



After the second molt, the larva has the peculiar bloom mentioned 

 above. The body is a pale pea-green beneath, and on the lower portion of 

 the sides. The black spines of the abdominal segments are as distinct as 

 in the full grown caterpillar. 



The fully developed larva may be recognized by its round jet-black 

 head and the peculiar glaucous green color of the body which resembles 

 that of the underside of the leaf. There are no lateral stripes or spots. 

 The thoracic segments are unmarked, but around each abdominal segment, 

 except the seconci, there are parallel double rows of minute dark dots or 

 warts I pi. 18, fig. 1 1]. 



The oval, brownish cocoon is -/c, of an inch in length and one half that 

 in diameter. 



The adult sawfly is a large thick black species, with the second and 

 fifth and part of the sixth abdominal segments a bright resin-red. 



Distribution. This insect appears to have become well established over 

 a considerable proportion of Canada and the New England States, New 

 York and Pennsylvania, and it will probably thrive wherever the larch 

 exists. 



Introduction. Dr f. A. Lintner states that this species was observed at 

 the Arnold Arboretum at Brookline Mass. in 1880 by Prof. C. S. Sargent, 

 who discovered the larva feeding on some European larches. Specimens 

 were submitted at this time to Dr H. Hagen who identified the species. 

 This is the first record of the insect's occurrence in America. 



Parasites. Dr A. S. Packard records the rearing of a number of 



