72 Farmers’ Bulletin 1169. 
the bark. These branches soon die and most of them fall to the 
ground. Until the middle of the following summer the larvae feed 
in the wood, loosely filling the mine with frass, though much of it 
may be expelled. The pupal cell is firmly walled with fibrous frass. 
One year is required to complete the development, though in more 
northern localities many of the larvae feed through the second year 
before pupating. A high mortality occurs in the larva stage, due to 
too many borers in the same twig or excessive drying of the branches. 
Remedy.—Gather and burn twigs as fast as they fall. 
Fig. 51.—Injury by the hickory barkbeetle to the twigs, buds, 
and base of leaves. (Hopkins.) 
HICKORY BARKBEETLE.” 
How destructive——For years the number of dead and dying hick- 
ory trees throughout this country has been increasing. In many 
instances the death of these trees has been traced to the work of 
the hickory barkbeetle. This beetle, then, constitutes a serious enemy 
of our hickory trees, which, unless prompt steps are taken, are in 
danger of being seriously depleted. ; 
4 Scolytus quadrispinosus Say, 
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