entomologist's report. 117 



upon the sap-wood as before, obstructing circulation and causing the 

 bark to dry and crack. The next year it reaches full size, and gnaws 

 channels in every direction, often cutting its way nearly through the 

 tree, and finally arranging for its exit, when it shall have become a 

 beetle, by catting a passage upward and outward through the bark, 

 the outer layer of which it does not quite penetrate. It then retires 

 to the heart of the tree, where it has prepared a sort of nest, in which 

 it reposes until spring, when it rapidly passes its transformations, and, 

 some time during May, makes its way out of the tree in its perfect 

 form the third year after the egg was laid. Some of the insects de- 

 velop every year, so that in a badly infected orchard the grubs may 

 be found in all stages of growth at any time during the summer. This 

 ■species feeds in the wood of pear, quince, Mountain Ash, and in the 

 native Juneberry, Wild Crab and several varieties of thorn. Orchards 

 planted in forest clearings are especially liable to its attacks. 



The Flat-headed Borer f Chrysobothris femorata, Fabr.) is also very 

 destructive to the apple, but, unlike the preceding species, is not con- 

 Fig. 7. fined to the pip fruits, but is a very general and 

 pernicious orchard pest, and attacks also cer- 

 tain shade-trees. It belongs to an entirely 

 different group of beetles — the Saw-horned 

 borers — and completes its development within 

 a single year. The beetle is flat, oblong, very 



Flat-headed Apple-tree Borer, i. j • ^ ^.x. • ■t.i.i. i. u i^- v. 



Larva and beetle (after Riley), hard, Varying from threc-cighths to one-half inch 

 in length, of a brassy dull greenish color above and coppery beneath, 

 and has short serrate horns or antenn;©. The boring grub or larva 

 is easily distinguished from every other borer by the enormously en- 

 larged and flattened fore-part of the body, which is three times the 

 width of the abdominal joints. The beetles delight in the hottest sun- 

 shine, and may often be seen at noonday resting on the trunks of fruit- 

 trees, perhaps laying their very minute yellow eggs in the cracks or 

 under scales of the bark. They fly readily, however, and must be 

 approached with great caution if it is desired to observe them at work. 

 The eggs hatch in a few days, and the young larvae cut their way 

 into the bark and begin feeding on the sap-wood, making broad shallow 

 channels, more or less horizontal, and often completely girdling the 

 tree before they are fullgrown. 



Recently transplanted trees, and those which are from any cause 

 somewhat weakly, are more liable to attack than those that are grow- 

 ing vigorously, as the young larvjc are often smothered in the sap of 

 the latter, As in the case of the Round-headed species, their presence 



