14 



female has transformed. The caterpillars before transforming fre- 

 quently crawl for some distance from the trees upon which they have 

 been feeding, and it therefore happens that the egg masses will be 

 found on fences and in all sorts of protected situations in which the 

 caterpillars hide during the day. The crevices in stone fences often 

 contain ver}- many of these egg masses, and knot holes in old trees 

 will also contain man}^ which would not at first be discovered. The 

 egg masses are found also in hollow trees, in crevices under rough 

 bark, on shrubbery, on buildings, in wood piles, in barrels, in boxes, 

 and among rubbish in dooryards. The moths seem to choose the 

 inner or lower surface of an object upon which to lay their eggs, and 

 therefore egg masses are placed out of sight perhaps as often as in 

 sight. 



The eggs hatch about May 1, and the young caterpillars begin imme- 

 diately to feed, usually upon the lower surfaces of the leaves. As 

 they grow they cast their skins several times, and as they become 

 larger they feed onlj^ at night, hiding during the daytime, usually in 

 clusters on the shady side of tree trunks, beneath large limbs, in holes 

 in trees, under loose bark, and in fact under any nearby shelter. It 

 is the habit of most of them to descend before daybreak upon the 

 trunks of the trees and to seek for such shelters as those just indicated, 

 returning after nightfall to resume their nocturnal feeding. 



The larvse usually become full grown about the 1st of July, and 

 then transform to pupse. The pupae are found in the same situations 

 as those we described for the egg clusters, but are found also in the 

 foliage of trees and shrubs. 



HOW THE INSECT SPEEADS. 



As indicated above, the bodies of the females are so heavy as to 

 prevent flight. Therefore the insect must be principally distributed 

 while in the caterpillar or larval condition. The caterpillars are active 

 crawlers, but as a rule do not migrate from the localities where they 

 were boi'n except when food is scarce. When young, and when there 

 is hardly enough food, the larv* spin down frotn trees by means of 

 silken threads and often alight upon vehicles of one kind or another, 

 and are thus carried often for great distances from the place of birth. 

 Trolley cars, carriages, automobiles, and bicycles are thus means of 

 transportation almost unlimited in their possibilities. The caterpillars 

 often crawl upon vehicles which happen to stand for anj^ length of 

 time in an infested locality, and thus may be carried great distances. 

 Sometimes even pedestrians aid unwittingly in this distribution, since 

 the caterpillars may drop by their threads upon the garments of a 

 person passing under an infested tree. 



275 



