Pine Sawfly. 



39i 



or end of June. The larvae are dusky greenish-grey with black 

 heads, a pale line along the back, and a dusky line with a pale 

 one on each side of it above and belcw ; the spiracles are placed 

 in the lower pale line. The sucker feet and underside of the 

 body are pale green. When full grown they are rather more 

 than half an inch in length, and then form an oval, pale 

 yellowish-brown parchment-like cocoon, both amongst the 

 needles and amongst heather, and in the earth, &c, beneath 

 the trees. Like the common Pine Sawfly this also is met with 

 in colonies, two individuals usually sitting on each needle. 

 They pupate in June, those kept under observation going into 

 this stage in the third week in June. Although needles and other 

 " cover " lay on the ground in the breeding cage, they pupated 

 in the earth just as described by Kollar. The females which 

 come from these cocoons lay their eggs in August and Septem- 

 ber in the needles just as is done by L. pint. Apparently the 

 eggs remain in the needles all the winter and hatch out in 

 early May. 



Preventive and Remedial Measures. 



It does not appear certain that sickly trees are more attacked 

 than healthy ones, but in any case attention should be given to 

 maintaining plantations in robust growth. All the Pine Sawflies 

 have many enemies. Amongst these must specially be men- 

 tioned mice and squirrels, which devour large numbers of the 

 larvae hibernating in the cocoons during the winter ; the cuckoo, 

 goat-sucker, and starling also devour numbers of the larvae and 

 adults. Numerous ichneumon flies also prey upon them. 



When young trees are invaded, the larvae may be easily 

 destroyed by crushing them with a gloved hand. This should 

 be attended to in the early stage of an attack, as at that time 

 the larvae are present in fairly compact groups, and are readily 

 dealt with. Shaking them from the trees on to cloths spread on 

 the ground is recommended, but is a less satisfactory method of 

 destruction than the other. Another plan is to place fresh pine 

 boughs beneath the trees and then jar the larvae off. All those 

 that fall to the ground collect on the boughs strewn about, 

 and can then easily be burnt. Trees that have been attacked 

 may have the ground around their trunks examined in winter, 



