168 
HALF HOURS WITH INSECTS. [Packard. 
one female, and the former appear to perform the chief part 
of the labor in the excavation of their galleries. With the 
timber beetles, on the other hand, the females are much the 
more numerous, and probably mine their galleries without 
any assistance from the other sex. M. Perris states of one 
of the species, that upwards of fifty females were met with 
in the burrows they had excavated, without a single male 
being found there.” 
As the young hatch out they run galleries either at right 
angles to the original one, or branching out in every direc¬ 
tion, though never intercrossing. In this way those that 
confine themselves entirely to the sap wood and inner bark 
loosen it, interrupt the circulation of sap and kill the branch 
fig. 133. 
affected. 
The Apple Twig Borer or Ampliicerus bicaudatus (Fig. 
133) is an exceedingly annoying beetle in the middle and 
western states. It somewhat resembles the bark 
boring beetles, but belongs to a different family. 
The grub is not known with certainty to burrow 
in the apple, but the beetles late in the summer 
bore into the twigs of the apple, beginning, ac- 
Amphicerus. CO rding to Riley, just above a bud or fork, whence 
it bores downwards an inch and a half into the twig, usually 
in wood of the previous year’s growth. “Both the male and 
female beetles bore these holes, and may always be found in 
them head downwards during the winter and spring months. 
The holes are made for food and protection, and not for 
breeding purposes.” As a preventive measure the infested 
twigs should be cut off and burned, the trees being looked 
over in the autumn. 
The Pricldy Leptostylus is the last borer which we have on 
our list of boring beetles. Dr. Fitch says that the grubs 
are like the young of the apple tree borer, and sometimes 
“occur in multitudes under the bark, forming long, narrow, 
winding tracks upon the outer surface of the wood, these 
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