84 BOARD OF AGRICULTURE. [Pub. Doc. 



beetle is of considerable importance, it is not to be com- 

 pared with the injury wrought by the larva?. These insects 

 destroy the epidermis, feeding upon the under sides of the 

 leaves. The latter turn brown and soon fall from the tree, 

 sometimes leaving it as bare as in midwinter. When the 

 larva> are full grown they are about one-half an inch in 

 length, light yellow in color, with black marking's arranged 

 along the back to form two conspicuous stripes. The ma- 

 ture larva? drop in large numbers from the tips of the over- 

 hanging branches, and pupate in masses in or near sheltered 

 places. A small per cent pupate beneath the bark of the 

 tree, or descend to its base. From these orange-colored 

 pupae in from five to ten days mature beetles emerge and 

 feed upon the foliage. 



There are two well-defined broods of the insect at Provi- 

 dence and on Cape Cod, and a partial second brood certainly 

 occurs at Springfield. The effect of the repeated defoliation 

 is to sap the vitality of the trees and invite the attacks of 

 other injurious insects, notably bark beetles. and borers, and 

 the death of the tree is often the ultimate result. 



While the spraying of the foliage is a difficult and often 

 an expensive undertaking, it offers the most effective means 

 of combating this insect. The insecticide used should be 

 some form of arsenate of lead, and, if possible, should be 

 thoroughly applied in the spring, when the beetles are feed- 

 ing. It is obvious that, if the hungry hibernating beetles 

 can be destroyed, further damage by the insect will be pre- 

 vented. The general custom, however, is to wait until the 

 foliage has fully developed, and then treat it with a heavy 

 spraying of arsenate of lead. This will destroy the late- 

 feeding beetles, and will remain in an effective condition 

 until after the eggs have hatched and the larva? have com- 

 menced to feed. One thorough spraying should preserve 

 the trees from injury throughout the season, although in the 

 case of the second brood it is sometimes necessary to make 

 an additional spraying late in July or early in August. 



Since Massachusetts abandoned the work of exterminating 

 the gypsy moth (Porthetria dtspar, Linn.), the numbers of 

 this insect have increased to an alarming degree in the east- 



