274 FARM FRIENDS AND FARM FOES 



Not all bacterial diseases of insects, however, are 

 helpful to man. The Foul Brood, which is so destructive 

 to honey-bees, and the dreaded flacherie of silkworms, are 

 both due to these microscopic germs. They cause great 

 losses to the bee-raising and silk industries. 



OBSERVATIONS FOR PUPILS 



1. In autumn look for flies that show the ring of spores around them. 



2. Look for diseased aphides or plant lice, especially between cab- 

 bage leaves and on clover plants. 



3. Keep watch for dead grasshoppers clinging to the tops of 

 wire fences or herbaceous plants. 



4. If you live in a region where chinch bugs are found, hunt for 

 dead, moldy specimens. 



5. If you live in a region where white flies are abundant, look 

 for those killed by fungus, and try spreading the disease. 



6. When you find any of these diseased- insects, place them in a 

 glass, add a few drops of water, and cover tightly. Watch daily for the 

 development of spores. Examine these under the microscope. 



7. Read this reference : — Nature Biographies, pages 89-95. 



Bacteria; highly magnified 



