Asemum striatum and Griocephalus ferus. 173 



In setting forth what I know of the life history of this 

 insect, with which I subsequently became more fully 

 acquainted, I will, in order to avoid repetition, mention 

 chiefly those respects in which it differs from that of 

 Asemum striatum. 



In the first place, it attacks large trees that are standing 

 and growing. When I discovered its habitat, the trees 

 appeared in no respect to differ from the surrounding 

 ones, but we now believe the vitality of these trees was 

 somewhat impaired by some cause or other. 



The wood in which the larvee were boring was by no 

 means dead ; for when cut, sap freely exuded. 



A careful examination revealed the fact that some of 

 the roots were dead or dying and inhabited by Asemum. 



The holes of Crioccphalus are usually further from the 

 ground than in the case of Asemum, when that insect 

 attacks trees. 



Judging from the length of time that the larva appears 

 full grown and lives in its completed burrow it would 

 appear to be much longer-lived than Asemum. 



The following, in addition to other evidence I have 

 gathered, proves that this larva lives for a very considerable 

 time in its completed burrow, viz. : early in August of last 

 year I carefully opened two completed burrows which ran 

 side by side ; the unobstructed portion of each was of 

 similar length, and I did not observe any difference. Each 

 contained a larva ; one of these was about to pupate, while 

 the other, judging from its sluggish movements, appeared 

 to be rapidly approaching that condition. I concluded 

 that both would provide imagos last year. The former 

 however pupated, while the latter simply underwent a 

 larval ecdysis, and I hope to rear it this year ; also the 

 largest larva I have ever seen I procured at that time, 

 but it will not mature till next August. 



I am of the opinion that Crioccphalus while in the larval 

 state always makes a hole for its exit as an imago and stuffs 

 up the entrance with gnawed-d own bark. I do not con- 

 sider however that I have sufficient evidence to be quite 

 positive on this point. It is interesting to note however 

 that. Griocephalus forces a very much larger quantity of 

 material into the end of its burrow than Asemum does, 

 the stopped-up part sometimes extending right through 

 the bark and into the wood itself where long wood-fibre 

 is used. 



