Reports to the Board of Agriculture. 37 
The trees should be cut down and burnt in the wintei when the 
larvae and pup* are safely housed in the wood. There are no 
remedies for the Sirex Flies, but all damaged and diseased timbei 
should be cleared out so as to check their increase. Damaged or 
unhealthy trees are mainly attacked. 
The Poplar Sawfly. 
( Cladius viminalis.) 
Some larvae sent to the Board ot Agriculture from Brondesbury 
attacking poplars were those of the Poplar Saw-fly ( Cladius 
viminalis). 
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 larvae 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 larvae 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 Beading, 
belonging to the genus Nematus, were reported as attacking willows. 
A great number of Saw flies feed on the willow and osier, and several 
of this genus Nematus have larvae 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 larvae sent and the description of those of that 
species given by Cameron. Another species has similar green and 
orange larvae, N. croccus , Fall., but the black markings in those from 
Beading did not agree. 
Nematus pavidus, Lep., does most harm to osiers in this country ; 
but they were not that species, as the orange marks are larger, and 
there were certain black dots which are not seen in N. pavidus. 
