196 NATURE STUDY AND LIFE 



in a belt, and so voraciously do the young caterpillars feed 

 that it has been estimated the occupants of a single tent 

 may cost a tree from 10,000 to 12,000 of its leaves, each 

 caterpillar eating two a day as it approaches maturity. 

 Early in June the caterpillars scatter from the trees in 

 all directions, seek out protected crannies about fences 

 and buildings, and spin their cocoons. Within these they 

 change to pupae, and after two to three weeks emerge as 

 moths, to repeat the life story. 



No insect is better adapted for rearing in the school- 

 room. Simply place the branch with its belt of eggs in a 

 bottle of water, feed as required with fresh leaves, and 

 thus let the children read the story in nature.^ 



The forest tent caterpillar, C. disstria, differs from the 

 above in having, instead of a white line, a row of light 

 dots down the middle of the back. The egg belt is cut 

 off squarely at the ends, the moths are light brown with 

 dark lines on the fore wings, and they do not build a 

 conspicuous tent. 



Cankerworms. — There are also two species : the fall 

 cankerworm, Anisopteryx pometaria, and the spring can- 

 kervvorm, Paleacrita, or A. vernata. The larvse are the 

 commonly known " measuring " or "inch " worms of shade 

 trees and orchards, but the moths and other characters 

 in the life story are not so generally understood. After 



1 A school in which this has been done for the past three years reports 

 that tent caterpillars have been practically exterminated from the district. 

 The eggs are collected and burned, each child being given credit for the 

 number he brings in, and any tents found in the spring are destroyed. The 

 caterpillars troop out of the tent to feed twice a day, mid-moming and 

 afternoon ; hence, in order to find them all at home the tents should be 

 destroyed in the early morning or evening. 



