388 



The Large Larch Sawfly. 



[OCT., 



the third week of August, were by the fourth week, in the great 

 majority of cases, full fed, and had left the trees and made their 

 way into the moss and litter on the ground below, in order to 

 make their cocoons. Here and there in such places on looking 

 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 Nematiis 

 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 twenty-seven to thirty 

 -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 1,000 feet and 1,500 feet above the sea leve!. 

 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 Neinatus Erichsoni in the Insect ]Vorld. — The large 

 larch sawfly belongs to the order Hymenoptera — an order con- 

 taining, amongst other insects, the bees, wasps, and ants. The 



