122 



[Octebep, 



I have observed that, when the eggs are hatched (or rather before that time), 

 the young larvao have their heads towards the bark, in which, during the summer 

 they busily feed. They are straight, white, footless, fleshy grubs, with a distinct 

 head and powerful mandibles, and I have observed them to be hatched about the 

 third week in May. In the autumn they assume the pupa state, and shortly after- 

 wards that of the imago. The perfect beetles, however, usually remain during the 

 winter months at the ends of the burrows formed by the larvaj, and emerge in 

 spring to continue their ravages, leaving a very distinct circular aperture ; on a 

 sculptured piece of bark all the very obvious holes are apertures of exit, those of 

 entry being obscure. 



It often happens that the parent beetles have made their burrows so close 

 together that the supply of bark is quite inadequate to the wants of the lai-vae, so 

 that their very abundance is its own remedy, and most of them perish. In other 

 instances the vitality of the bark ceases before the larvae are full fed, the tree 

 having fallen too long when attacked, so that but a small proportion usually come 

 to maturity. 



I have remarked the preference of H. fraxini for fallen timber, nevertheless it 

 does occur on living trees. On almost any young ash tree I have found marks 

 shewing that a burrow had been formejd and a brood perfected, and that the tree is 

 now exfoliating the destroyed bark. Sometimes I think the growth and vigour of 

 the trees appear to have been decidedly checked by them j and, though I have not 

 met with an example, I doubt not that trees are occasionally killed by this beetle. In 

 other instances trees with these marks appear to be uninjured. Where they are 

 injurious, they may be extirpated by cutting down affected trees, stripping off and 

 burning the bark, &c, ; but as I suspect that it is the want of dying timber which 

 forces them to attack living trees, I would suggest that placing fresh logs, during 

 the spring months, in the neighbourhood of affected trees, as traps, and destroying 

 the beetles which come to them, would be more effectual. 



1 have found one tree which owed its fall to the operations of H. crenatus. The 

 beetle had obviously been in possession many years ; it had commenced the attack 

 near the foot of the tree, and destroyed the bark round more than half its 

 circumference, and to a height of 15 or 20 feet, the hmb above being dead. The 

 portion of bark longest destroyed had fallen away, — the wood beneath being in 

 possession of Sinodendron and Dorcus, and rapidly rotting. The tree was blown 

 over in one of the gales of last winter. I have also found H. crenatus sparingly in 

 several other trees, all pollarded or otherwise sickly. Unlike H. fraxini, H. crenatus 

 takes two years to undergo its transformations, the larvae assuming the pupal state 

 at the end of the second summer, so that at present full-grown larvao and perfect 

 beetles are both to be met with. Felled timber would be unable to support this 

 long larval existence. H. crenatus accordingly is never met with except in living 

 trees ; and, while an affected tree continues alive, I believe that none of the 

 beetles desert it for another. They economise it as much as possible, the destroyed 

 bark being more completely riddled and devoured by them than by any other 

 beetle of the family I am acquainted with ; the burrows of the larvao are much 

 more irregular also, so that it is impossible to find one of those perfect maps of their 

 voyages (as in H. fraxini) which have secured for the XylophcLga as a family the 

 name of " typographers." Last winter the blown down tree I have mentioned 



