THE HICKORY TWIG-GRIDLER. 



289 



small hickory branch only three inches long. Professor Haldeman 



states that "both sexes are rather rare, particularly the male, 



which is rather smaller than the female, but with longer 



antennce. The female makes perforations (Fig. 113, b) 



in the branches of the tree upon which she lives, which 



are from half an inch to a quarter of an inch thick, in 



which she deposits her eggs (one of which is represented 



of the natural size at 'Fig. 113, e). She then proceeds 



to gnaw a groove, of about a tenth of an inch wide and 



deep, around the branch and below the place where the 



eggs are deposited, so that the exterior portion dies and 



the larva feeds upon the dead wood." In the case 



noticed by Professor Haldeman, the tree attacked was 



the shag-bark hickory {Carya alba) and the incisions 



were so shallow as not to break off until after the larva 



had matured within it, ornearly a year after the girdling. 



But in most of the cases observed by Messrs. Walsh and Riley upon 



pear and persimmon trees, the " twig was girdled so deeply that it 



Fig. 113.— Hickory 

 twig girdler.— After 

 Riley. 



Fig. 114. — Tree cut by the twig girdler — Haldeman rfcZ. 



broke off and fell to the ground with the first wind, and while the eggs 

 that had been laid in it by the mother-beetle were still unhatched. 

 Even in a girdled hickory twig 0.35 inch in diameter, which we have 

 now lying before us, but a third part of its diameter is left in the mid- 

 5 ENT 19 



