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 
antennae. 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 uutil after the larva 
had matured within it, or nearly 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 twiggirdler — Haldeman del 
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 
