352 



PROTECTION AGAINST INSECTS. 



old, on poor soils and with a sunny aspect. They also attack 

 young growth and trees up to the age of 120 years. Border 

 trees especially suffer. 



The larvae till half-grown eat the needles in dense companies 

 of 60 to 80 and more. When young they merely gnaw the 

 edges of the needles; later on they eat them in short strips 

 parallel to the mid-rib, which they leave intact. An attack 



Fig. 182. 3 cocoons of 

 the Pine sawfly on 

 pine bark. 



(Natural size.) 



Fig. 183. 2 empty cocoons of the 

 Pine sawfly on an oak-twig. The 

 upper one has lost the lid. 



by the pine sawfly may be at once recognised by the remaining 

 yellowish, thread-like mid-ribs (Fig. 184). 



The older caterpillars only leave short stumps to the needles. 

 The first brood chiefly devour 1 -year-old needles, and the 

 second brood those of the current year. The larvae also gnaw 

 the soft young bark in patches, often down to the wood. 

 After the crowns of larger poles are stripped, smaller Scots 

 pine poles, underwood, and young plantations are attacked. 



