1022 THE FRUIT INDUSTRY IN NEW YORK STATE 



gations have also' shown that insects play an important role 

 as disseminators of diseases. It is now believed that various 

 wood-boring insects are in part responsible for cankers and other 

 disorders of the trunks of fruit trees. The wounds and holes in 

 the bark produced by these pests certainly make it possible for 

 disease-producing organisms to establish themselves in the tree. 



The adult round-headed borer is a handsome beetle about three- 

 quarters of an inch long and light brown in color, with two white 

 stripes across thorax and along each wing. The adult of the asso- 

 ciated species is a dull metallic brown in color and about one-half 

 inch in length. The life histories of the two insects are very 

 similar. The eggs are deposited in crevices or slits in the bark, 

 and from these there develop the pale grubs, which may be observed 

 working beneath the bark and which are familiar to most growers. 



Treatment. The trees, especially in young plantings, should 

 t be inspected every fall and spring for discolored areas in the 

 bark or for wounds from which there is exudation of sap or for 

 sawdust-like castings. When such are detected the borers should 

 be cut out by means of a strong, sharp knife. Grubs buried 

 deeply in the heartwood may be destroyed by probing with a 

 piece of wire or by injecting carbon bisulphide into the burrows, 

 after which the openings should be immediately sealed with 

 grafting wax. As unthrifty trees are more susceptible to attack, 

 the needs of the orchard in other respects should be given careful 

 attention for the purpose of stimulating the trees to outgrow the 

 injuries and ward off subsequent attacks. 



INSECTS THAT INCRUST THE BARK 



The San Jose Scale 



San Jose scale, Aspidiotus pemiciosus Comstock, ranks as one 

 of the worst pests of fruit trees. Besides the pear, it attacks the 

 cherry, apple, peach, plum, currant practically all our common 

 orchard trees and bush fruits. It thrives also on many shade trees 

 and ornamental shrubs. 



Large numbers of this scale appear as a grayish, scurfy deposit, 

 not unlike a coat of ashes. The bark becomes rough and dull in- 

 stead of having a smooth and polished appearance. Branches that 

 are infested with large numbers of the insect usually show dead 



