198 NATURE STUDY AND LIFE 



The White-Marked Tussock Moth, Orgyia leiicostigma. — The 

 larvae are among our most beautiful caterpillars, but they 

 may become so numerous as to strip a city's shade and 

 fruit trees of their foliage. They feed upon almost all of 

 our deciduous trees and even on fir and larch and spruce 

 as well. As in case of the cankerworm, the females are 

 wingless, but unlike it there are two broods a year, and 

 instead of going into the ground, they make their cocoons 

 in the trees, pupate there, and the females crawl out of 

 the cocoons and lay the eggs in a white frothy mass upon 

 them. The white ^gg masses are conspicuous objects on 

 the trees in winter, and since the insect is two brooded 

 and may at any time become too numerous to control, 

 they should be gathered and destroyed. This is another 

 instructive insect to rear in the school vivarium. 



The Fall Webworm, HypJiantria text or. — In July, after 

 the tent caterpillars have run their course, the trees are 

 again disfigured by large irregular masses of webs, so 

 conspicuous that their destruction ought to be a simple 

 matter of common sense. This insect is single brooded ; 

 both male and female moths are provided with wings and 

 hence spread more rapidly and are not so easily con- 

 trolled as the two moths just described. The caterpillars 

 burrow in the ground to pupate and do not emerge until 

 the following July. 



Cutworms. — These are caterpillars of the various species 

 of the owlet moths, genus Agrostis. Their plan of work 

 is to cut off every tender plant in the garden even with 

 the earth. Both caterpillar and moth are nocturnal, the 

 moth laying her eggs on plants near the ground during 

 the latter part of summer. At first the larvae feed upon 



