756 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSIOxV. 



by this insect. Their habits are very similar to those of the fir saw- 

 fly, Lophyrus ahietis of Harris, though they are more gregarious than 

 he describes that species to be. They eat the needles down to their 

 insertion, thus stripping one twig after another. The larvse spin their 

 cocoons among the leaves, and the flies appeared about the middle of 

 August. Out of thirty one individuals but one was a male." 



Professor Riley, in his i!finth Report, states that this saw-fly in its 

 larval state is destructive in Indiana, Illinois, and Wisconsin. He 

 states that the perfect insects are quite irregular in coming out of the 

 ground, many of them issuing in May, but others not until toward the 

 end of summer. "On opening cocoons that had passed the winter I 

 have found many yet containing the larva the latter part of June, while 

 others of the same brood had become flies six weeks before. * * * 

 In ovipositing the female saws beneath the epidermis on one of the flat 

 sides of the leaflets, and pushes into the slit an egg, which is whitish, 

 ovoid, .08"^™ long on an average. As the egg swells it forms a con- 

 spicuous bulging of the epidermis, and the mouth of the slit opens and 

 exposes more and more a portion of the egg.^^ It is preyed upon by an 

 ichneumon fly {Limneria lophyri Riley). 



Dr. F. W. Goding, of Rutland, 111., sent me some of these worms, 

 September 23, 1884, with the remark that they had been defoliating 

 the white pine. " Over a quart was destroyed beneath one tree by 

 kerosene." 



Larva. — Average length, .80 inch, though many will measure an inch. A soft, 

 dingy-white worm, having often a greenish or bluish line superiorly. On all joints 

 but the first, which is entirely white, two obloug square black spots along the back, 

 and another somewhat rounder spot each side ; these become somewhat diffused on 

 the thrse latter joints, forming on the last a single black patch. Three black thoracic 

 legs, fourteen abdominal and two caudal prologs. Thoracic joints largest ; the three 

 last smallest and taperiug. Some are marked very regularly, while in others the white 

 space on the back between the spots on segments 5, 6, 7, and 8 is much wider than 

 between the others. This is probably a sexual difference, since those thus marked 

 are shorter, thicker, and of a yellower white than those regularly marked. After 

 each change of skin the head is at first white like the rest of the body, with the usual 

 eye-spots black. No markings while young. 



A cluster of about twenty larvae probably of this species occurred on a 

 twig of the white pine August 9, at Brunswick, Me. These molted for 

 the last time August 11, the epicranium splitting apart on each side of 

 the clypeus. They spun cocoons, but the flies did not appear. 



L. ahietis, with regular but faint bands, is evidently the primitive 

 form, and L. abhotii and the other spotted larvte the secondary and later 

 forms. How did the double dorsal line originate ? 



Larva. — Head black, body flesh-white, the black spots contrasting very much with 

 the pallid ground-color of the body. A dorsal row of eleven pairs of black spots, 

 each spot oblong and about one-third as wide as long. A row of eleven lateral black 

 nearly square spots, which are a little longer than broad. Supra-anal area black. 

 Thoracic feet black ; eight pairs of abdominal pale feet. Length 22'"™. 



