INSECTS INJURIOUS TO THE APPLE AND PEAR 



591 



be painted over the trunk so as to form a thick coating. Others 

 recommend a thick coating of whitewash to which a little Port- 

 land cement is added to make it more adhesive. These should 

 be applied by the middle of May and as often as need be to keep 

 the trunk covered until late summer. If the trees are gone over 

 every fall and spring, the egg scars and burrows of the young 

 larvae may be detected and they may be cut out while still in the 

 sap-wood, without much injury to the tree. When the borers 

 get into the heart-wood it is almost impossible to dig them out with- 

 out doing more injury to the tree, but they may sometimes be de- 

 stroyed by injecting carbon bisulfide into the burrows and plugging 

 the aperture with putty or clay. Where a tree has been nearly or 

 quite girdled, it may sometimes be saved by bridge-grafting. 

 Orchards kept free of grass and weeds and trees with smooth 

 healthy bark are much less affected. 



The Flat-headed Apple-tree Borer * 



This species is more abundant than the preceding, but does 

 less damage. It prefers trees which have been weakened or are 

 diseased, and attacks almost all of the common orchard trees as 

 well as numerous shade and forest trees, so that it is everywhere 

 common. The species is 

 found from southern Can- 

 ada to Mexico. The larvsB 

 live just beneath the bark, 

 where they hollow out 

 broad flat channels which 

 extend slightly into the 

 sap-wood. The infestation 

 may be detected by the 

 discoloration of the bark. 



d 



Where abundant they will 

 often completely girdle 

 young trees, thus causing 

 their death, and they are 



* Chrysobothris femorata Fab 



FIG. 446. The flat-headed apple-tree 

 borer (Chrysobothris femorata Fab.): 

 a, larva; b, beetle; c head of male; 

 d, pupa twice natural size; (After 

 Chittenden, U. S. Dept. Agr.) 



frequently found abundant under 

 Family Buprestidoe. See Chittenden, I.e. 



