Specific Pests 161 
attached to crevices in the bark or other similar shelter, 
and in the ground if soft enough, wintering in this condi- 
tion. The small, pure white or brown and black-dotted 
moths issue in June or July (the first southern brood in 
May), and lay their bright golden eggs in large clusters on 
leaves, usually on the under side and near the end of the 
branches, from which the caterpillars issue within a week 
or ten days. 
Besides the damage to the foliage, the disagreeable habit 
of the worms of dropping from the trees is obnoxious in 
city streets. Poplars, willows, box-elder, ash, cherry, elm, 
and basswood suffer most from this pest, but nearly all other 
trees are attacked if the food supply is scarce in a year of 
excessive development. 
The easiest method of combating the pest is to cut off and 
burn the webs, or burn them on the tree with a torch, with 
proper caution to avoid injuring the tree. Spraying with 
arsenical poisons when the young caterpillars appear is 
also effective. 
Bag Worm. The bags, one to two inches in length, in 
which the caterpillars enclose themselves while feeding and 
in which they finally pupate, are the readiest sign of their 
presence. ‘These bags are made of pine needles, bits of 
foliage and bark, and are gradually built up by each indi- 
vidual around itself. The caterpillars appear in May and 
early June, and at once begin the construction of their 
bags, first carrying them upright on their posterior body, 
then, as they grow heavier, hanging down. In spite of 
this impediment, they spin down and wander freely; finally, 
in September, attaching themselves hanging down from 
twigs, they pupate within the bag. The inconspicuous 
males, with black hairy body and glassy wings, fly in Sep- 
tember and October; the females are wingless, hairless, and 
