324 Proceedings of Royal Society of Edinburgh. [sess. 
been attacked, but with no insects remaining to suggest the pest. 
In such cases, as an aid to determination the following may be 
helpful : — 
(a) The larval tunnels may arise from a common centre. — There 
is just the chance of confusing the work with that of the Scoly- 
tidse, but in the case of Pissodes no mother tunnel is found, only 
larval ones. Sometimes the eggs are laid singly. The resulting 
single tunnels are difficult to determine, but if they are very long 
one can pretty safely diagnose them as the work of a Pissodes. 
(b) The tunnels are long , a considerable distance intervening 
between the place of egg-laying and the pupa bed. Recently I 
took specimens of P. pini with larval tunnels a foot long. 
If the tunnels, for some reason or other, instead of winding on, 
form a sort of interlacing network confined to one place, then the 
work may be confused with the larval borings of some of the 
longicorn beetles. More than once I have found under the bark 
Pissodes larvrn and Longicorn larvae working side by side — e.g., 
once in an old felled silver fir, where among hundreds of larval 
piceae were very many grubs of a Rhagium. 
(c) The pupal beds with their coverings of sawdust and wood- 
chips. 
The pupa of Hylobius abietis also lies in such a bed, but is 
chiefly confined to stumps and roots ; besides, it is larger. 
( d ) Typical host plants : — 
P. notatus, on pine and in pine cones. 
P. jpini , on pine, rarely on spruce. 
P. piniphilus, on pine. 
P. piceae, on silver fir. 
P. harcynice , on spruce. 
P. scabricollis , on spruce. 
My experiments were conducted with the first three in the 
above list, all three being found in Great Britain. 
Pissodes notatus (F.). 
How I got my material. 
In the month of June 1895, while engaged in entomological 
work in Bavaria, through the kindness of Professor Pauly, the 
