DESTRUCTIVE ANIMALS, BIRDS, INSECTS 121 



after year in the same place, the foliage of the larch is often 

 so reduced that the health of the tree is affected, and it then 

 becomes liable to attack by the larch canker. It must there- 

 fore be considered as a very serious pest. No remedial 

 measures can be taken on a large scale, but the chief object 

 of the woodman should be to keep the larch in healthy 

 condition by the accepted sylvicultural methods. Late frosts, 

 and wet or cold weather, kill off millions of this insect. 



Hymenoptera (Saw/lies). 



Pine sawfly (Lophyrus 

 pint). 



The larva of this insect has 

 twenty-two legs (whereas 

 that of a moth has sixteen), 

 and is of a dull green 

 colour. It is social, and 

 feeds in colonies. The saw- 

 fly appears in April and 

 May, and again in July and 

 August. The female does 

 not appear to fly, but crawls 

 along on the twigs and 

 needles of pines. She cuts 

 slits into pine needles and 

 lays an egg in each slit. 

 The larvae hatch out in May and June, and the second 

 brood in August and September. They pupate in long 

 leathery dark brown cocoons. They attack chiefly Scotch 

 pines, preferring sickly trees, and eat the needles in companies 

 of eighty to one hundred, leaving the midrib untouched. 

 When disturbed they bend the front part of their bodies into 

 the shape of the letter S. 



The insect is very destructive, but unfortunately it is 

 difficult to deal with on a large scale. In young plantations 



Fig. 6. Pine needles, with larvae 

 and cocoon of L. pini, L. 



