THE CAl'RJCORN-BEETLES. 99 



The leaves of the oak are rarely shed before the branch 

 falls, and thus serve to break the shock. Branches of five 

 or six feet in length and an inch in diameter are thus severed 

 by these insects, a kind of pruning that must be injurious to 

 the trees, and should be guarded against if possible. By 

 collecting the fallen branches in the autumn, and burning 

 them before the spring, we prevent development of the 

 beetles, while we derive some benefit from the branches as 

 fuel. 



It is somewhat remarkable that, while the pine and fir 

 tribes rarely suffer to any extent from the depredations of 

 caterpillars and other leaf-eating insects, the resinous odor 

 of these trees, offensive as it is to such insects, does not 

 prevent many kinds of borers from burrowing into and de- 

 stroying their trunks. Several of the Capricorn-beetles, while 

 in the grub state, live only in pine and fir trees, or in timber 

 of these kinds of wood. They belong chiefly to the genus 

 CaUidium, a name of unknown or obscure origin. Their 

 antennae are of moderate length ; they have a somewhat 

 flattened body ; the head nods forward, as in Stenooorus ; the 

 thorax is broad, nearly circular, and somewhat flattened or 

 indented above ; and the thighs are very slender next to the 

 body, but remarkably thick beyond the middle. The larvae 

 are of moderate length, more flattened than the grubs of 

 the other Capricorn-beetles, have a very broad and horny 

 head, small but powerful jaws, and are provided with six 

 extremely small legs. They undermine the bark, and per- 

 forate the wood in various directions, often doing immense 

 injury to the trees, and to new buildings, in the lumber 

 composing which they may happen to be concealed. Their 

 burrows are wide and not cylindrical, are very winding, and 

 are filled up with a kind of compact sawdust as fast as the 

 insects advance. The larva state is said to continue two 

 years, during which period the insects cast their skins several 

 times. The sides of the body in the pupa are thin-edged, 

 and finely notched, and the tail is forked. 



