188 Rev. G. A. Crawshay on the 
and dead Picea and other firs, and these latter trees have always 
been untouched by the beetle. 
In timber-yards also I have observed piles of Larix, many of 
which contained the beetle, with Picea close by infested by Sirex 
and other insects, but free from any trace of Vetropiwm,and both 
trees coming from the same plantation. 
In the same way I have always found the species avoid Pinus 
sylvestris, Linn. I have examined hundreds of this conifer dying 
and dead in Tetropium localities and found them unaffected by 
Tetropium, though the work of Criocephalus, Asemum and Rhagiwm 
was visible. 
The 2 2 which I enclosed on Picea and Pinus were restless and 
tried to eat their way through the muslin, while those enclosed on 
Larix settled down at once and oviposited freely, the larve hatching 
out and spreading over the entire surface of the log, 
In confinement then, and under compulsion, 7’. gabrieli is capable 
of living in Pinus and Picea, but prefers Larix ewropexa, multiplying 
in this tree so fast that the second brood will completely kill a dying 
tree of average dimensions, using up all the inner bark. 
Lire Cyciz.—The egg is laid in the outer bark. The larva 
consumes the soft bast, the cambium layer itself, and sometimes grazes 
superficially the youngest sapwood. Thus destroying the vital juices 
it soon kills completely a sickly tree. 
When full fed it either excavates a pupa-cell under the surface of 
the outer bark, or burrows in the wood and pupates there. 
The life cycle occupies a year. Appended are data concerning 
this (p. 189). 
THE Imaco.—In a hot temperature the beetles are very active 
in their movements, running rapidly over the surface of the bark, 
chasing each other, or lying quite flat to it, basking in the sunshine. 
They have also a peculiar habit of standing motionless, 
almost on tiptoe, with the body well away from the bark. 
The hind-legs being longer than the fore-legs, that part of 
the body is slightly tilted up in the air. 
More generally they creep under the plates of the bark and hide 
themselves entirely. Pairs secrete themselves under the lamine of 
the bark in cop. The species is, on the whole, fond of seclusion, and 
doubtless this is why it has escaped notice so long. There may be 
many imagos on a tree but very few visible at a time. I have placed 
as many as a dozen on a foot of 9-in. larch-pole and it has been 
difficult to find one at times. 
They appear to be exclusively diurnal in their habits. I have 
kept numbers in large boxes and flower-pots out of doors, covered 
