INSECTS 



219 



great many trees besides apple trees. The round-headed 

 borer is a serious enemy of the apple and quince and is 

 sometimes found in pear trees. The grubs of these borers 

 live in the tree trunk about three years and then change to 

 the pupa stage a few weeks before emerging as adults. 



The best remedy is to keep the adults from laying their 

 eggs on the trunks. This is done by tying tar paper or 

 wire gauze about the trunks. The bottom of the material 

 should be slightly in the ground and the top securely tied 

 to prevent the beetles from crawling in. These protectors 



Fig. 137. 



-Round-head apple-borer: a, larva; 6, pupa; c, adult. (From Smith's 

 "Economic Entomology.") 



should be renewed before the egg-laying season of June and 

 July. Above these screens the trees should be whitewashed 

 or sprayed with lime-sulfur. 



The San Jose Scale. — These insects were probably 

 introduced into this country from China and were first 

 found in America near the city of San Jose (Ho-s a'), California. 



This insect is probably the worst enemy of fruit trees. 

 It has sucking mouth parts, and not only sucks the sap 

 from leaves and fruit but also from the more tender 

 branches. 



The breeding season of the insect lasts throughout the 

 warm summer months, being checked only by frost. Large 



