164 DESrRVCTIVE INSECTS. 



half their growth, still living on the sap-wood. They cease 

 feeding during the winter and remain in their burrows beneath 

 the surface of the soil. By the end of the second year they 

 have penetrated deeper into the solid heart-wood, and their 

 burrows are closely packed behind them with their castings. 

 After another winter's rest they continue their work in the 

 solid wood, and toward the end of the season gnaw outward 

 to the bark. With the aid of its castings a cell is then formed 

 in which the full-grown larva (Figs. 213 and 214) remains until 

 spring, when it transforms to a pupa (Fig. 216). The pupal 

 stage is said to last about twenty days, and in May or June 

 the pretty beetles emerge through a smooth, round hole cut 

 with their powerful jaws. 



This borer is a very difficult insect to control. It is nearly 

 impossible to save a young tree. When small, the larva may 

 be cut out with the point of a knife. If deeper in the wood, 

 it may be extracted or punched to death in its hole with a 

 flexible wire. 



It will avail nothing to inject any substance into the large 

 round holes made by the beetles in emerging from the tree. 

 But it is reported that if kerosene be applied wherever the 

 castings of the larva are seen sticking through the bark, the 

 oil will permeate the burrow and kill the larva. 



Some have successfully destroyed similar borers in their 

 burrow by injecting carbon bisulphide from an oil-can into the 

 openings from which castings are protruding and then plug- 

 ging the hole with putty or hard soap ; the deadly fumes of 

 this liquid penetrate all through the burrow and quickly kill 

 the borers. It is a diflScult matter to prevent this borer from 

 getting into a tree. Several thicknesses of newspaper or tarred 

 paper carefully wrapped about the base of the tree and tied 

 often forms quite an effective barrier. The many different 

 washes recommended afford but little protection in our ex- 

 perience. Examine the trees twice each year, in May and 

 September, and dig out or destroy all larvae which can be lo- 

 cated. Clean culture will help in the warfare against borers. 



The Flat -headed Apple-tree Borer {Chrysobothris femo- 

 rata). — This is usually a much less dangerous, though more 

 abundant, insect than the preceding species. The pretty 

 beetles (Fig. 218) are day-fliers. They attack by preference 



