INSECT ATTACKS AND REMEDIES 143 



wasp is common on the outskirts of London, 

 and its borings may be seen on some of the 

 old and diseased Scotch pines on Hampstead 

 Heath. Owing to the borings or holes being 

 perfectly circular in shape and the edges sharply 

 defined, they are readily distinguished from 

 those of any other timber-destroying insect. 



The Pine Sawfly (Lophyrus pint] . Fortu- 

 nately, this insect is not abundant in the 

 British Isles, though on the Continent the 

 damage it does in the pine forests is by no 

 means inconsiderable. The insect may readily 

 be recognised by its wide, flattish body, and 

 usually dark appearance. Having attained to 

 full size in the trees, they form cocoons among 

 the foliage or on the stems, and remain in this 

 condition until the following spring, when, in 

 April or May, the perfect insects make their 

 appearance. The male is considerably smaller 

 than the female, while the full-grown cater- 

 pillar, which is of a greenish-yellow colour, 

 with a row of black spots on either side, is 

 about an inch long. The remedial measures 

 are not at all easy, especially when a large 

 number of trees are attacked ; but single 



