308 EXPLANATION OF PLATE. 



hatched from the eggs they are light in color and covered with whitish 

 hairs. In a few hours they assume a dark hue. They usually remain 

 on or near the egg-cluster until they change in color, and should the 

 weather be cold they sometimes remain for several days in a semi- 

 torpid condition upon the egg-cluster. If the temperature is favorable 

 they usually search for food before they are twenty-four hours old. 

 During the first few weeks of their existence they remain most of the 

 time on the leaves, feeding mainly on the under side. Their feeding 

 habits are so uncertain that no rule can be given which will apply to 

 all individuals, but before they are half-grown they generally begin to 

 manifest their gregarious instincts. At that time and for the rest of 

 their existence as caterpillars they spend a large part of the day clus- 

 tered in sheltered situations, and feed principally at night, going up the 

 trees and out on the branches after dark and returning before daybreak. 

 When they are so abundant that the food supply is insufficient they 

 evince much restlessness, and feed in numbers during all hotirs of the 

 day and night. They may then be seen hastening to and fro, both up 

 and down the trees. Those which have fed sufficiently are at once 

 replaced by hungry new-comers, and the destruction of the foliage goes 

 on incessantly. 



At such times the trunks and lower branches of trees are covered with a 

 moving mass of caterpillars, hurrying throngs are passing and repassing, 

 and nearly every leaf or denuded stem bears up one or more of the feed- 

 ing insects. The rustling caused by their movements and the continual 

 dropping of excrement is plainly audible. On tall trees the larger 

 caterpillars appear to crawl to the higher limbs, and they seem to prefer 

 to feed well out toward the end of the branches. They do not feed gre- 

 gariously except when in great numbers ; therefore they seldom strip 

 one branch only, as do the larvae of the Euvanessa antiopa, but scatter 

 throughout the trees, eating a little from each leaf Early in the 

 season when they are small and few in numbers, their ravages are 

 scarcely noticed ; but as they grow larger and more numerous, their in- 

 roads on the tree decrease the foliage area night by night, until suddenly 

 all the remaining leaves are eaten, and the tree is stripped in a single 

 night. 



Food Plants. 

 The gypsy moth is known to destroy the foliage of nearly all native 

 and introduced trees and plants of economic importance. The list of 

 its food plants includes nearly all evergreen and deciduous trees, most 

 bushes, shrubs, vines and vegetables, and it has been seen to eat grass 

 and grain. Wherever the caterpillars become numerous they move 

 slowly, devouring nearly every green leaf and bud as they go. They 

 feed during a much longer season than the canker worm or the tent 

 caterpillar. In the months of June, July and August, 1891, trees which 

 had been stripped early in the season and whose leaves had again put 

 out were ao-ain defoliated by these caterpillars and kept bare all sum- 

 mer ; therefore, not only was all prospect of a fruit harvest destroyed, 

 but many trees were killed by this continual defoliation. 



