290 Annual Report for 1912 of the Zoologist. 



larch sawfly, though it would appear that this insect is 

 increasingly troublesome in the north of England. 



The wide distribution and common occurrence of Argy- 

 resthia laevigatella on larches is very remarkable in view of 

 the fact that it was first recorded in England only five years 

 ago, by Dr. Somerville and Mr. Bennett. There may be 

 something in the suggestion that its work, when previously 

 noticed, had been attributed to the familiar pine weevil. At 

 all events it appears to be only too common now. Several 

 instances in which poplar trees had been killed by the large 

 poplar longicoi'n, Saperda carcharias, were reported. It is 

 very likely that the work of this insect is often confused wuth 

 that of the goat moth, which it roughly resembles. When a 

 poplar tree is perforated by large borings without any goat-like 

 smell, the presence of the beetle should be suspected. In its 

 case the entrance holes will be all low down on the trunk, and 

 the examination of a dead trunk shows that the burrows 

 converge as they mount, all being near the middle of the wood 

 at a few feet from the ground. The consequence of this 

 method of working is that the tree is greatly weakened at its 

 base, and it is not rare for one or more of a row of poplars to 

 be blown down in a gale before the presence of a serious pest 

 has been suspected. 



This localisation of the entrance holes makes it much easier 

 to combat the beetle attack than that of the goat moth, whether 

 by the injection of insecticides in the case of infested trees, or 

 by the protection of sound trunks. Protective applications 

 need not extend to a greater height than five feet from the 

 ground, and trees of which the lower part of the trunk has 

 been daubed in June with a mixture of clay and cow dung are 

 fairly safe. Such protective measures are particularly desir- 

 able in the case of poplar nurseries if any old poplar trees are 

 near at hand. 



Of course it is possible that the goat moth and the beetle 

 may both be at work on the same tree, but a more frequent 

 associate of the beetle in the poplar is the large " clear-wing " 

 moth, TrochiJium apiforme. It also works at the base of the 

 trunk ; indeed it often attacks and hollows out the larger roots 

 which protrude from the ground. When the joint attack has 

 proceeded at all far no extraordinary gale is required to snap 

 the tree off short near the ground. 



Animal Parasites. 



In this section the dividing line between the veterinary 

 and zoological departments is indefinite, and some of the 

 applications received have been referred to the Royal 

 Veterinary College. Advice has been given in the case of 



