INSECTS INJURIOUS TO FOREST TREES 513 



in the burrows may be killed by injecting a little carbon 

 bisulphide into the hole after the castings and exudations have 

 been cleared from the entrance. The hole in the bark should 

 then be filled with cement. 



The Leopard-moth (Zeuzera pyrina) .The leopard-moths are 

 beautiful white moths that have their bodies and wings marked 

 with many black spots. The larvse may 



be found in any part of the tree, but they 



more often attack the smaller limbs. As 



they work principally in the sapwood, 



the affected limbs are usually killed. The 



only satisfactory method of treatment is 



to cut out all the infested wood and burn 



it. It is easier and safer to sacrifice the 



whole tree if it is badly infested. The 



female moths do not fly readily, so the 



infestation does not spread rapidly except 



in places where the trees are very close 



together. 

 The Oak-primer (Elaphidion mllosum). 



When oak-pruner beetles occur in con- 

 siderable numbers the trees are made un- 

 sightly by the dead branches which later 



fall to the ground. The damage is done 



by the larvse, which bore in the twigs and 



finally cut them off. As the larvae pupate 



in the fallen twigs they should be gathered 



and burned before the adult beetles issue. 



This insect attacks many kinds of shade 



trees, and sometimes may be injurious to v w , 



. , . , rlG. 244. WOrK 



certain fruit trees also. of oak twig-girdler, 



On the Pacific Coast there is another AgrUus sp. (About 

 smaller borer, Agrilus politus, that attacks 2/3 natt 

 and kills the small branches of the oak trees. As the twigs 

 are killed, but not cut off, the tree soon becomes very ragged 

 and unpleasing in appearance. Such infested twigs should be 

 cut off some time during the winter. 



33 



