568 



NEW YORK STATE MUSEUM 



Poplar sawfly 



Trichiocampus viminalis Fallen 



Orange-yellow, black-spotted larvae, about t/ io inch long, feed side by side on the 

 foliage of poplars in the early part of June. 



This species was brought to notice by Dr J. A. Lintner, under the 

 name of Aulacomerus lutescens as he was unable to refer it to 

 any described species. 



Life history. He states that he found a number of the larvae in the 

 early part of June feeding in parallel rows side by side, on two leaves which 

 had been eaten from the tips, downward. The scars made by oviposition 

 were observed on the leaf stalks and on the leaves, 30 in the case of one, 

 and 28 in the case of the 'other. He adds that both lots were probably 

 deposited by one female. The larvae feed heartily, and when all but the 

 basal parts had been eaten on one leaf it was abandoned for another. In 

 some cases some of the larger veins were left uneaten. The larvae fed in 

 company till mature, though as they approach this period, they separate 

 into smaller groups and would at once do so if disturbed by the removal of 

 some from the leaf. They commenced to spin irregular cocoons between 

 the leaves on which they had been feeding June 25, and by the 27th all 

 had spun up. The perfect insects appeared July 13 to 18. A second brood 

 of this species was observed in August. A large number of leaf petioles 

 bore the marks of oviposition, the eggs being placed in two parallel rows 

 on opposite sides, usually on the upper side of the leaf stalk, the rows 

 apparently being made one after another, as they were seldom of equal 

 length, and each for the. most part, having the punctures in a perfectly 

 straight line. The foliage of the infested trees was so badly eaten that it 

 was necessary to pick off such infested leaves as could be conveniently 

 reached, in order to destroy the larvae and prevent further depredations. 

 The work of this insect was also observed by Dr Lintner on other trees 

 that same year. The young of this second generation were not carried to 

 maturity, and consequently nothing further could be learned regarding its 

 life history in America. This species is stated by an European authority 



