DESTRUCTIVE INSECTS. 175 



a vesicular, water-proof varnish. There is thus but one brood 

 of the caterpillars each year, and by far the largest portion of 

 the insect's life is spent in the egg, usually from July until 

 the following April. 



Maple shade trees and sugar-bushes, as well as some other 

 forest trees, sometimes suffer severely from hordes of large 

 hairy caterpillars, which are closely allied to the apple-tree 

 tent-caterpillar, and have been called the Forest Tent-cater- 

 pillar (Clisioscampa disstria). One of them is shown in Fig. 

 239. Sometimes this insect invades orchards and proves a 

 more serious enemy than its near relative. Its life-history is 

 practically the same as that of the apple-tree tent-caterpillar, 

 but the two species are easily distinguished in the egg, cater- 

 pillar, and moth stages. 



The egg-rings of the forest species are shorter and blunter 

 at the ends ; the caterpillars have a row of whitish spots down 

 the middle of the back instead of a continuous white stripe ; 

 the moths have an oblique band of a deeper tint across each 

 front wing, while those of the apple-tree tent-caterpillar are 

 crossed by a similar band bordered with narrow white stripes. 

 The popular name of forest tent-caterpillar is misleading, as 

 the caterpillars do not make a tent, but simply spin a thin 

 silken mat or carpet on the bark where the whole family rests 

 when not feeding. 



Several parasitic and predaceous insects prey upon this 

 forest species and usually keep it in subjection. In sugar- 

 bushes and other forest lands man must depend largely upon 

 these enemies to control the pest. 



The best and cheapest method of combating both the apple- 

 tree and the forest species of these tent-caterpillars is to cut 

 off the small branches which bear the eggs, during autumn or 

 winter, and burn them ; do not leave them on the ground, 

 for they will often hatch as readily there as on the tree. 

 A most convenient implement for this work is a tree-pruner 

 (see page 102). The eggs are seen at a glance after a little 

 practice. Every ring of eggs thus removed, which is done 

 in a few seconds, totally prevents a nest or colony of 

 caterpillars in the spring, and is far more expeditious and 

 effectual than the usual modes of burning the nests, or brush- 

 ing off the caterpillars with poles at a later period. Enlist the 



