322 Proceedings of Royal Society of Edinburgh. [sess. 
harmful to the alder ; the leaf -mining larvae of the lively Orchestes 
fagi ; the grub of Balaninus nucum , familiar in nuts ; and the 
Anthonomus larvae, so troublesome to the apple grower. Harmful 
in the mature stage is Hylobius abietis , the pine weevil, one of the 
greatest scourges in our conifer plantations and nurseries. 
The Genus Pissodes. 
The species belonging to this genus have a longish rostrum. 
Hear the middle of the rostrum the elbowed antennae are inserted, 
their long basal joint almost reaching the small, slightly-projecting 
eyes. The prothorax is narrowed in front, and its posterior 
margin, on examination with a lens, may show two slight excava- 
tions. The scutellum is round and raised. The elytra quite cover 
the abdomen. Femur untoothed, tibia straight and with a curved 
hook at the point. The third joint of the tarsus is broad and two- 
lohed, and the terminal fifth joint ends in two simple claws. 
Life History. — In life history most of the Pissodes agree. The 
females lay their eggs in the hark of conifers. The hatched-out 
grubs, starting, it may be, from a common centre, gnaw long 
winding tunnels in the bark, the whole perhaps showing a star- 
like pattern, although this design is not so frequently met with in 
Pissodes notatus and Pissodes piniphilus. The full-fed grubs gnaw 
in the outermost layers of the wood a little bed or cradle, oval in 
shape, and here, covered by a cushion of wood chips and sawdust, 
they pupate, the imago biting its way when ready through bed- 
cover and bark, leaving a small round hole. 
The grubs living and tunnelling between the bark and the 
wood interfere with the conduction of the sap, and the infested 
plants weaken and die. While the larval stage is the very 
injurious one, the adult beetles may weaken the plant by the 
punctures they make with their probosces when feeding. 
Of the twenty or so species known, five are well known in 
Great Britain or the Continent as pests on coniferous trees — viz., 
P.*pini , P. notatus , P. piniphilus , P. picece , P. harcynioe. 
My experiments have been with the three British species, 
P. notatus , P. pini , P. piniphilus. 
