Asemum striatum and Criocephalus form. 169 



and I have always observed that the insect is closely 

 followed up by Bhagium. 



It is thus clear that Asemum striatum and Bhagium 

 bifasciatum together constitute one of the most potent 

 (though unobtrusive) helps to forestry. For there is good 

 reason for supposing that there is never a considerable 

 number of Scotch firs felled in the New Forest but these 

 two insects turn the opportunity to good account and 

 speedily reduce the stumps to manure. 



The former ever retreats before the progress of decay 

 until retreat is no longer possible, while the latter delights 

 in decay and feeds on decaying wood until it thus reduces 

 the whole stump to powder, with the exception of the 

 thinnest layer of outer wood which hides its depredation 

 within. It often happens that a stump, the upper-surface 

 of which is covered with Asemum holes, and would appear 

 to contain larvae of that insect, when tapped, completely 

 collapses and appears but a mass of dust and manure. 

 Bhagium is not what we may call a hard-working insect 

 and does not make a hole of exit unless necessary, but 

 uses any convenient fissure, or the holes of Asemum, for 

 the purpose of exit. 



The life-cycle of Asemum is as follows, viz. : — 



At the end of May or early in June, a number of eggs 

 are inserted between the scales of the bark on the sides of 

 the stump or exposed portions of the thick roots. The 

 young larvae soon hatch and for some time feed on the 

 bark itself. Having worked their way through the bark 

 they do not bore between the bark and the wood as the 

 Callidiidie do, but penetrate through the outer layer of 

 wood, when, if they were deposited in the side of the 

 stump, they commence working downwards, just under 

 the surface of the wood, making as they proceed galleries, 

 the calibre of which is in one direction slightly larger 

 than their own bodies and in the other direction much 

 wider. These galleries wind about and their margins are 

 more or less tortuous. The larvae when about half-grown 

 have proceeded some distance down the stump, and they 

 then connect the burrows with the outside by means of 

 small holes. Up to this point, as they progressed, their 

 galleries were completely and tightly filled behind them 

 with wood-dust and refuse, which they had compressed 

 so tightly that when dry it is almost as hard as the sur- 

 rounding wood. Till this period, the decay of the stump 



