T h: IB 



North American Eiitomologlst 



Editor: A. R. GROTE. Tublijliers: KEIXECKE & ZESCII. 



Buffalo Society of Natural Sciences. 500 Main Street, Buffalo, N.Y. 



Vol. 1. OCTOBER, l^ro. INo. 4. 



On a New Predaceous Lepidopterous Insect. 



l>y J. IIexky Comstock., Entomologist, U. ^^. J)ept. of Agrie. 



[PLATE IV.] 



A\'Iiilc studying u colony of the cottony maple scale {Pulvinarin iinnt- 

 merabilis, liathvon) which was found on a branch of JVegundo aceroi- 

 (les in AVashington, I was surprised, to find a Pyralid larva living 

 within the cottony mass excreted hy one of these insects. On farther 

 examination it was found that very many of the hark - lice afforded 

 retreats for similar larvae. This, with the fact tliat the eggs 

 deposited l)y such individuals, or the young lice developed from them 

 had been destroyed, indicated that the Pyralid larvae were preda- 

 ceous. One of these larvae was placed in a glass tube with a bark- 

 louse, the eggs of which had not been destroyed. These eggs 

 had just hatched and the cottony excretion was swarming with the 

 yoinig lice. The larva soon made its way under this mass, and after 

 spinning a delicate silken tube about its body began to devour the 

 young lice greedily. The larva was placed in the tube at 3 P. M.; 

 at 9 A. M. the following day it was found that fully one third of 

 the lice had been destroyed, showing that if these larvae occur in 

 great numbers they must prove an efficient chock to the spread of 

 tliis pest of our shade trees. It is an interesting fact bearing upon 

 this point that as yet this bark-louse has not become common in 

 Washington. Careful search revealed only a few sporadic individuals 

 except upon a single box-elder tree ; and there the predaceous cater- 

 [tillars were so numerous that it was with difficulty that any scales 

 \vere found not infested by them. 



Although the caterpillar is well protected, living as it does within 

 the mass of cottony excretion, it spins about its body a delicate silken 

 tul)e. This tube reminds one of that si)un by Galleria ; but it is 

 more delicate ; and Avhen spun within tlie cottony mass, it is with 

 difficulty distinguished from it. When a l)ranch is thickly infested by 

 Pvlrinarid these tubes extend from one liark-louse to another. 'J'lie 



