46 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 
one found many cocoons and some caterpillars which had not 
yet spun up. I brought away with me abundant material from 
which I hope next year to clear up points in the biology. 
On the 31st of August caterpillars were still to be found on 
the trees, but only after a very careful search. In addition to 
well-grown caterpillars, I took on this date very small cater- 
pillars, not more than a few days old. One must not rashly 
assume that these tiny caterpillars were the result of a second 
brood of sawflies. There is the possibility that they were from 
eggs laid by sawflies that had issued from cocoons of 1905, but 
later in the season than the great majority. This /Vematus 
infestation in Cumberland is serious, not only from the loss that 
it has already occasioned, but also because there are several 
other large tracts in the neighbourhood planted with larch which 
are in danger of infestation. There had been the intention 
too, on the affected estate, to plant another 27 to 30 acres 
with larch, but this work has had to be held over on 
account of the presence of the sawfly. 
Altogether in this neighbourhood an area of over 300 acres 
has been attacked. Examination of other larch woods near, and 
of isolated larches here and there at a greater distance, showed 
that there were still uninfested places, but the danger of infection 
is great. That the attack is not limited to the Merehouse 
Plantation and immediate neighbourhood is seen in a letter to 
the Board from Mr Smith Hill, saying that since the outbreak 
at the Dodd Wood he has found cocoons in abundance in 
Coomb Plantation. Coomb Plantation is on the other side of 
the Derwent Valley from the Merehouse Plantation. It is 
situated four miles from Keswick in a north-westerly direction, 
and lies between rooo feet and 1500 feet above the sea-level. 
The plantation is sixty years old, and extends to 200 acres. 
Mr Smith Hill has also been informed of attack on Shoul- 
thwaite Wood, near Thirlemere Lake. 
Position of Nematus Erichsoni in the Insect World.—The large 
larch sawfly belongs to the order Hymenoptera—an order con- 
taining, amongst other insects, the bees, wasps, and ants. The 
family of Hymenoptera which has the greatest interest for the 
forester is the Zenthredinide, or sawflies. The sawflies are so 
called from the fact that the ovipositor of the female is modified, 
typically, to form a sawing apparatus, by which the openings are 
made in leaf or twig for the reception of the eggs. The two saws 
