THE BARK-BEETLES. 
87 
account was written in 1824, bv Mr. Macleav. An abstract 
of his paper may be found in the fifth volume of the “ New 
England Fanner.” * The laiwae or grubs of these bark- 
beetles resemble those of the Hyliirgus terebrans^ or pine bark- 
beetle already described. Like the gmbs of the weevils, 
they are short and tliick, and destitute of legs. 
The red cedar is inhabited bv a veiw small bark-beetle, 
named by Mr. Say Hyliirgus dentatus^ the toothed Hylurgus. 
It is nearly one tenth of an inch in length, and of a dark- 
brown color; the wing-cases are rough ^^dth little grains, 
which become more eleA’ated towards the hinder part, and 
are arrano-ed in longitudinal rows, with little fuiTows between 
them.^ The tooth-like appearance of these little elevations 
suggested the name given to this species. The female bores 
a cylindrical passage beneath the bark of the cedar, dropping 
her eggs at short inters^als as she goes along, and dies at the 
end of her burrow when her eggs are all laid. The grubs 
hatched from these proceed in feeding nearly at right angles, 
fonning on each side numerous parallel furrows, smaller than 
the central tube of the female. They complete their trans- 
fonnations in October, and eat their way through the bark, 
wliich will then be seen to be perforated with thousands of 
little round holes, tlu’ough which the beetles have escaped. . 
Under the bark of the pitch-pine I have fomid, in com¬ 
pany with the pine bark-beetle, a more slender bark-beetle, 
of a dark chestnut-brown color, clothed vdth a few short yel¬ 
lowish hairs, with a long, almost egg-shaped thorax, which is 
very rough before, and short ^rfng-covers, deeply punctured 
in rows, hollowed out at the tip like a gouge, and beset 
around the outer edge of the hollow with six little teeth on 
each side. This beetle measures one fifth of an inch, or 
rather more, in length. It arrives at maturity in the autumn, 
but does not come out of the bark till the following spring, 
at which time it lavs its eggs. It is the Tomicus exesus. or 
excavated Tomicus ; the specific name, signifying eaten out 
* Page 169. 
