REPORT ON FORESTS. 227 



Exactly how much harm they do is perhaps a question^ Their 

 life history is not well known, and just how much living tissue 

 the larva requires to bring it to the pupal stage is yet to be 

 ascertained. It is reasonably certain, Jiowever, that they require 

 two or more years to reach maturity, and that their presence 

 alone does not indicate any serious danger to the trees. 



There are other of these large grubs, feeding in decaying 

 stumps, like the species of Osmoderma, black or brown in color, 

 broad and a little flattened, with a peculiar, somewhat leathery 

 odor, only a feeble indication of the intensely disagreeable 

 effluvia of the .giant Dynastes of the more southern States, 

 which appears in New Jersey only as a very occasional visitor. 



Smaller white grubs are nibbling away at the edges, so to 

 speak, near the exposed ends of the log or trunk, leaving a 

 little dry crust between themselves and the outer air. These 

 are species of Valgus and allies, which, though they be common 

 enough, are rarely seen except by the entomologist. When 

 decay has proceeded well along, and the log has become unfit 

 for most other species, the larva of Passalus comes along and 

 does the finishing work. 



This is also a white grub, grows to be almost two inches long, 

 and differs from the others by having four legs only. The 

 beetle is oblong, black, an inch and a quarter or more in length, 

 somewhat flattened and with a little curved horn on the head, 

 whence it derives its specific name, cornutus. When this insect 

 gets through with a log or stump, it can be kicked to pieces 

 without much effort, and of real wood fibre little is left beside 

 the shell. 



Stumps are in the same category with fallen trees and logs, 

 the same general types of insects attacking them and causing 

 their reduction to dust. Stumps, however, are more likely to 

 be invaded by Termites, and when these take possession nothing 

 else will be found. Ants, particularly the black and brown car- 

 penter ants, are found in logs before they are much advanced in 

 decay. 



In this superficial sketch only the more prominent types of 

 insects concerned in forest injury or in reducing a dead tree to 

 vegetable mould have been mentioned, those forms chiefly that 

 any one with a little ability in observing can find without much 



