THE ENEMIES OF INSECTS 251 



swift-moth (Hepialus lupulinus) are similarly afflicted by 

 Cordyceps entomorhiza, while allied fungi destroy larva?, 

 pupa 1 , and imagines of many kinds. One causes the silk- 

 worm disease known as " muscardine." In France and 

 Germany attempts have been made to utilise some of these 

 fungi for the destruction of pest-insects, such as the grubs 

 of chafer beetles. It is doubtful, however, whether this 

 method could be employed satisfactorily on a large scale. 



Bacteria cause epidemic diseases among insects, the 

 most serious from an economic standpoint being the 

 "flacherie" of silk-worms and the "foul brood" of hive- 

 bees. 



