EXPERIMENT STATION BULLETINS 



187 



THE FALL WEB-WORM. 



(Hyphantiia cuiiea, Dru.) 



Early in autumn or late in summer the larsre nests or webs of this caterpillar are 

 seen in the branches of many fruit and shade trees. 



Unlike the apple-tree tent-caterpillars, Avhich work in our apple trees in the 

 springtime, the larvse of this species build a web as far as they work. Both live in 

 colonics, liut the spring tent-caterpillar builds a small tent, from which the larvae go 

 out to feed and to which they return. The fall web-worm, on the other hand, extends 

 the nest as it becomes necessary in order to accommodate the growtii of the colony. 

 The colony is the result of a cluster of eggs laid by a single moth, usually on a leaf. 



Fall weh-worm (Ili/phantria citiica), from C. V. Riley, insects of Jiissouri, Sd Rep. 



The caterjdilars of this insect are hairy fellows, a little less than two inches in 

 length. There is one brood a year in the North, though further South it is said that 

 there are more. The caterpillars are light in color, yellowish, with a darker stripe 

 on the back. When full grown they are covered with long whitish hairs. It has been 

 said that the web is extended as the size of the colony increases. This goes ou 

 until the larvae are very nearly full grown, when they leave the shelter and seek 

 convenient retreats for spinning up in cocoons. This is done in almost any sheltered 

 place, under bark or rubbish, or under the surface of the soil. The moth that comes 

 from the cocoon measures about one and one-fourth inches from tip to tip of its 

 extended wings. It is usually \nu-Q white, though many specimens have dark spots on 

 the wings. The insect feeds on one hundred and twenty species of shrubs and 

 ornamental trees. *^ and the damage done is often very serious. Specimens were col- 

 lected on wild cherry at Chatham on August 28, 1900. A specimen of the female 

 moth and an egg-cluster just laid were sent by Mr. Geismar on July 12. 



re:medie.s. 



The cocoons may bo collected in the winter time whenever that is feasible. Spraying 

 the ntfected trees with one of the arsenites is another remedy that is often found useful. 

 The best remedy, however, after th(J larvir have obtained a start, is to apply a 

 torch to the nest and burn them out. A bundle of oil-soaked rags or sponges tied to a 

 long pole, or a porous brick attached in the same way, answers the purpose perfectly. 

 With this the nest may be entirely demolished and the occupants singed without 

 doing more than slight damage to the tree, if care is taken to move the torch quickly. 

 Of course, the earlier this is done the better. 



*Dr. L. O. Howard. Year-book. Dept. of Agr. for 180.'.. i». 376. 



