SOME TREE PESTS 



the young leaves, which soon become perforated. 

 In about ten days the egg-laying begins, the fe- 

 male feeding and laying eggs alternately during 

 a period of several weeks. The yellow spindle- 

 shaped eggs are laid on the under surfaces of the 

 leaves, from which the young larvae emerge in 

 a week's time and begin feeding upon the tender 

 foliage. The great damage is done by the larvae. 

 When full-grown they are about half an inch in 

 length, light yellow in color, with black mark- 

 ings arranged on the back to form two conspicu- 

 ous stripes. When they are mature they drop 

 from the tips of the branches and pupate in 

 masses in sheltered places. The mature beetles 

 emerge from the orange-colored pupae in five to 

 ten days and begin to feed upon the foliage. 

 There are two broods a year. Repeated defolia- 

 tion saps the tree of its vitality and the weakened 

 condition invites the attack of other injurious 

 insects bark-beetles and borers and the death 

 of the tree is often the result. Two female bee- 

 tles, observed for four weeks, laid respectively 

 four hundred and thirty-one and six hundred 

 and twenty-three eggs. 



Orgyia leucostigma Tussock Moth severely 

 injures the Elm, Linden, Horse-Chestnut, Silver 

 Maple and other trees. Its increase is largely 

 controlled by parasites. The eggs are laid by 

 wingless females in late summer or autumn on 



181 



