THE BARK-BEETLES. 87 



account was written in 1824, by Mr. Macleay. An abstract 

 of his paper may be found in the fifth volume of the " New 

 England Farmer." * The larvae or grubs of these bark- 

 beetles resemble those of the Hylwrgm terebrans, or pine bark- 

 beetle already described. Like the grubs of the weevils, 

 they are short and thick, and destitute of legs. 



The red cedar is inhabited by a very small bark-beetle, 

 named by Mr. Say Sylurgus 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 with little grains, 

 which become more elevated towards the hinder part, and 

 are arranged in longitudinal rows, with little furrows between 

 them. The tooth-like appearance of these little elevations 

 suggested the name given to this species. The female bores 

 a cyhndrical passage beneath the bark of the cedar, dropping 

 her eggs at short intervals 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, 

 forming on each side numerous parallel furrows, smaller than 

 the central tube of the female. They complete their trans- 

 formations in October, and eat their way through the bark, 

 which will then be seen to be perforated with thousands of 

 little round holes, through which the beetles have escaped. 



Under the bark of the pitch-pine I have found, in com- 

 pany with the pine bark-beetle, a more slender bark-beetle, 

 of a dark chestnut-brown color, clothed with a few short yel- 

 lowish hairs, with a long, almost egg-shaped thorax, which is 

 very rough before, and short wing-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 lays its eggs. It is the Tomicus exesus, or 

 excavated Tomicus ; the specific name, signifying eaten out 



* Page 169. 



