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1889-90.] Mr William Somerville on Larix europcea. 
Larix europeea as a Breeding-Place for Hylesinus pini- 
perda. By William Somerville, D.GEc., B.Sc. 
(Read July 7, 1890.) 
The special point that I wish to bring before the Society relates 
to a case of the common larch being made use of by Hylesinus 
piniperda for purposes of oviposition. As occasion demands, this 
insect has been found to utilise as a breeding-place every species of 
Pinus, but, so far in Europe or North America, no case has been noted 
of any trees belonging to the genus Larix having been similarly 
attacked. In Asia an observer, namely, Middendorff, has recorded 
one case which came under his notice in the district of the Bogan id a, 
in Siberia, in 71° north latitude ( Sibirische Reisen , Band iv. Theil 
i. p. 603). 
In the beginning of April of this year, in the Upper Ward of 
Lanarkshire, on a south-west slope, at an elevation of some 800 feet, 
I found that several larches, which had been felled during last 
winter, were attacked by large numbers of this insect. In its com- 
pany I also found Hylastes palliatus , but by far the greater number 
of galleries were the work of Hylesinus piniperda. During the past 
three months these trees have been kept under close observation, 
with the result that I find one or two particulars in which the 
attack of this insect on the larch differs from its mode of attacking 
the Scots pine. 
The greater abundance of fluid resinous matter in the larch, as 
compared with the Scots pine, seems to have considerably interfered 
with the work of forming galleries. I noticed that all the trees 
lying in the wood were not attacked, but only those at one side, 
where they were within the shade cast by a dense wood of pines 
situated to the south. This, I believe, to be due to the fact that 
the cambial activity and formation of resinous solutions were 
retarded in these trees owing to their not being directly reached by 
the sun’s rays; whereas the cambium and cortex of those trees fully 
exposed to the sun were so saturated with resin as to be safe from 
attack. Even in some of the trees attacked I found unfinished 
galleries quite full of resinous secretions, and containing the dead 
bodies of the male and female insects, which had doubtless been 
j drowned or suffocated by the resinous exudations. 
