68 
COLEOPTERA. 
States is the Brenthus (^Arrhenodes) septemtrionis * of Herbst 
(Fig. 34), the Northern Brenthus, so named because most 
Fig. 34. of the other species are tropical insects. It 
is of a mahogany-brown color ; the wing-cases 
are somewhat darker, ornamented with nar- 
-JB L row tawny-yellow spots, and marked with deep 
V furrows, the sides of which are punctured ; the 
f W I thorax is nearly egg-shaped, broadest behind 
the middle, and highly polished. The com¬ 
mon length of this insect, including the snout, is six tenths 
of an inch ; but much larger as well as smaller specimens 
frequently occur. The Northern Brenthus inhabits the white 
oak, on the trunks and under the bark of which it may be 
found in June and July, having then completed its trans¬ 
formations. The female, when about to lay her eggs, punc¬ 
tures the bark with her slender snout, and drops an egg in 
each hole thus made. The grub, as soon as it is hatched, 
bores into the solid wood, forming a cylindrical passage, 
which it keeps clear by pushing its castings out of the orifice 
of the hole, as fast as they accumulate. These castings or 
chips are like very fine sawdust; and the holes made by 
the insects are easily discovered by the dust around them. 
When fully grown, the grub measures rather more than an 
inch in length, and not quite one tenth of an inch in thick¬ 
ness. It is nearly cylindrical, being only a little flattened 
on the under-side, and is of a whitish color, except the last 
segment, which is dark chestnut-brown. Each of the first 
three segments is provided with a pair of legs, and there 
is a fleshy prop-leg under the hinder extremity of the body. 
The last segment is of a horny consistence, and is obliquely 
hollowed at the end, so as to form a kind of gouge or scoop, 
the edo-es of which are fiirnished with little notches or teeth. 
It is by means of this singular scoop that the grub shovels 
the minute grains of the wood out of its burrow. The pupa 
* A mistake undoubtedly for septemtrionalis. It is the Brenthus maxillosus of 
Olivier and Schbnherr. 
