Reports to the Board of Agriculture. 37 



The trees should be cut down and burnt in the winter when the 

 larvse and pupte are safely housed in the wood. There are no 

 remedies for the Sirex Flies, but all damaged and diseased timber 

 should be cleared out so as to check theii- increase. Damaged or 

 unhealthy trees are mainly attacked. 



The Poplar Sawfly. 



{Cladius viniinalis.) 



Some larvai sent to the Board of Agriculture from Brondesbury 

 attacking poplars were those of the Poplar Saw-fly {Cladius 

 viriiinalis). 



The eggs are laid on the leaf-stalk of the poplar, which becomes 

 Swollen and bends over on each side so as to cover the eggs. 



The young larva are green with black heads ; at the second 

 moult they become orange and green with twelve large black marks 

 on each side, etc. When full fed they are entirely orange with the 

 black marks very prominent. 



The double cocoon is usually spun beneath loose bark or may be 

 between the leaves. They feed in companies and eat the epidermis 

 usually on the under side of the leaf. 



These is one brood which occurs in August and September. 



The insect is very common and the larvte sometimes do some 

 harm to the leafage of young trees. 



They also occur on the willow and osier. 



Sawfly Larvae on Willows. 



Some Sawfly larvae, sent by a correspondent from Heading, 

 belonging to the genus Nematus, were reported as attacking willows. 

 A great number of Sawflies feed on the willow and osier, and several 

 of this genus Nematus have larva3 very similar to the two sent. It 

 was not possible to say for certain what the species was unless the 

 perfect insects were bred, but it was probably the species known as 

 Nematus conjugatus, Dbm. ; but at the same time there were slight 

 differences seen in the larv?e sent and the description of those of that 

 species given by Cameron. Another species has similar green and 

 orange larvse, N. croceus, Fall., but the black markings in those from 

 Eeading did not agree. 



Nematus pavidtis, Lep., does most harm to osiers in this country ; 

 but they were not that species, as the orange marks are larger, and 

 rthere were certain black dots which are not seen in N. pavidus. 



