230 HORTICULTURE FOR SCHOOLS 



arsenate of lead to one hundred gallons of water, just after 

 the blossoms drop and before the calyx-lobes have closed 

 over the end of the little apple. 



In cases in which there is a bad infestation in the orchard, 

 more than one spray must be used. Usually two at least are 

 necessary, the second being applied from two to three weeks 

 after the first. Later spraying must be timed by the egg- 

 laying of the moths or the occurrence of the little larvae just 

 hatched from the eggs. Thoroughness in the application of 

 the spray is the most important factor in successful control. 

 341. Borers (Figs. 117-118). Much damage sometimes 

 results to fruit-trees from the attack of borers. Of the 



numerous species, the flat-headed 

 borer is the one most commonly seen . 

 East of the Rocky Mountains, a spe- 

 FIG. ii7. La^TcJ flat-headed cies of beetle known as the round- 

 headed borer occurs commonly. 



The flat-headed borer in its mature state is a little dark 

 colored beetle, with metallic reflections. But it is the larval 

 form that is of chief concern. This larva has a small head and 

 a tapering body. Just back of the head 

 is a greatly enlarged segment which 

 looks to the casual observer as if it 

 were a part of the head. Because of 

 this enlarged segment, the insect has 

 the name of the flat-headed borer. FlG . ii 8 . Adults flat-headed 



The mature insect deposits its eggs 



on the bark of the tree. From the egg hatches the larva just 

 described. This larva feeds at first just beneath the bark 

 of the infested tree. Sometimes it completely girdles the 

 tree. After feeding for a time, it begins to burrow into the 

 heart-wood. The burrow is of a characteristic oval shape and 

 thus may be distinguished from that of the round-headed 

 borer which is circular in cross-section. 



The adult of the round-headed species is a beautiful 



