APPLE INSECTS — BUDS AND FOLIAGE 



67 



The Apple Leaf-skeletonizer 

 Canarsia hammondl Riley 



The small greenish or })rownish caterpillars of this insect are 

 about i an inch long, with 4 black, shining tubercles on the back 

 just behind the head, and usually with a broad darker stripe 

 along each side of the back. They live upon the upper side of 

 the leaves under a thin web of silken threads, where they eat out 

 the green pulpy portion, leaving a network of veinlets and giving 

 the foliage a skeletonized and rusty or highly blighted appear- 

 ance. There are two 

 broods of the insect 

 annually, one work- 

 ing in midsummer 

 and the other, usu- 

 ally the more nu- 

 merous, in Septem- 

 ber and October. 



^ _ ,, ^ Fig. 72. — The apple leaf-skcletonizer moth (X5). 



Sometimes the cater- 

 pillars work gregariously in a nest of several leaves webbed 

 together. Pupation occurs on the leaves and the second brood 

 hibernates in the pupa stage. ' This Pyralid moth (Fig. 72) 

 has an expanse of about one half an inch ; the front wings 

 are glossy purplish-brown, each marked with two silvery- 

 gray transverse bands. 



This leaf-skeletonizer is most common in the Mississippi 

 Valley, where it is sometimes quite destructive in nurseries and 

 young orchards. It works practically only on apple trees, 

 rarely attacking plum and quince. 



Two or three parasites attack it. As the caterpillars feed 

 openly on the surface of the foliage, they can be easily killed 

 with a poison spray applied as early in the' season as their 

 skeletonizing work is noticed. 



