208 N. H. AGR. EXPERIMENT STATION. [Bulletin 139 



and under surfaces of the leaves are eaten until thej' become dry 

 and brown. (See figure 1.) The new webs of the fall web- 

 worm might readily be mistaken for the work of the young 

 brown-tail moth caterpillars, which also spin more or less of a 

 web over the foliage upon which they feed; but the web-worm 

 caterpillars appear earlier than those of the brown-tail and by 

 the time the latter appear their webs cover a large part of a limb 

 and the caterpillars are an inch or more long, while the young 

 brown-tail caterpillars feed only on the leaves at the tips of the 

 limbs, never form large webs, and never become over one-fourth 

 of an inch long before they enter their winter webs for hiberna- 

 tion early in September. When the foliage within one web is 

 entirely consumed the caterpillars will leave it and form a new 



Fig. 1. Apple leaf denuded by young Webworms. 



web upon a fresh branch and thus a tree soon becomes covered 

 with these unsightly webs. These webs (fig. 2) are easily distin- 

 guishable from those of the Tent Caterpillar, which occur in the 

 spring and never in late summer, as the Tent Caterpillar makes 

 a tent-like web at the fork of a limb and never encloses foliage 

 within it. When the food in the webs becomes scarce the older 

 caterpillars scatter over the tree where food is more abundant, 

 and as soon as full grown seek a place in which to spin their 

 cocoons. The full grown caterpillars are about an inch long 

 and quite "woolly," being thickly covered with long white and 

 black hairs, which project from numerous prominent black tuber- 

 cles. The younger caterpillars are pale yellowish with brown 



