74 FRUIT INSECTS 



pillars leave their mines, and rolling over the edge of the leaf 

 feed beneath for a short time, then line these retreats heavily 

 with a silken cocoon within which they pupate. There are 

 several broods each season. The tiny, dark, steel-gray moths 

 emerge in the spring and measure only J of an inch across 

 the expanded wings. This miner is widely distributed 

 across the northern half of the United States, and is ap- 

 parently more common than the spotted tentiform miner. 

 In some cases two-thirds of the leaves in orchards have been 

 distorted by from 2 to 4 of the unspotted mines, yet no very 

 serious injury resulted. The insect also attacks pear and wild 



cherry foliage. 



References 



Brunn, Cornell Univ. Exp. Sta., Second Rept., pp. 151-154. 1883. 



Forbes, 4th Rept. State Ent. III., pp. 51-57. 1889. 



N. Y. (Geneva) Agr. Exp. Sta. Bull. 180, pp. 131-134. 1900. 



The serpentine leaf-miner (Nepticala pomivorella Packard). 



The tiny, dark, emerald-green caterpillars, about yV of ^^ 

 inch long, make narrow, tortuous or serpentine mines, often 

 2 inches in length and less than yV of ^t^ i^ich wide just beneath 

 the upper surface of the leaves of the apple and pear. The 

 first half or two thirds of the mine is broader and nearly filled 

 with a continuous zigzagging thread of black excrement. 

 The insect is quite common in Canada and the northeastern 

 United States. In October, the tiny green caterpillars are 

 sometimes seen hanging by silken threads from the leaves. 

 They soon find their way to the twigs, where they spin small, 

 oval, dense, brown cocoons about | of an inch long on the back, 

 often in a crotch. These cocoons resemble, and could be easily 

 mistaken for, Lecanium scales. In May the caterpillars trans- 

 form through brilliant green pupae to the minute, shining, pur- 

 plish-black moths with tufted, reddish-yellow head, that emerge 

 early in June. Thus far no very serious injury has been re- 

 corded by this interesting little Tineid serpentine miner. 



