142 REPORT OF STATE GEOLOGIST. 



Vegetable Parasites. — Among the most common parasites of 

 loeuf^s is a vcgetahlo fiino^us, which in wet seasons attacks them, 

 saps their veins and in time destroys many of their tissues. One 

 often finds, after a long damp spell in late summer, many dead speci- 

 mens of our larger locusts clinging to the tops of weeds. A close ex- 

 amination will show that their bodies are soft, and issuing from them 

 in many places are the ends of fungous tubes. This locust fungus, 

 Empusa grilK Frcs, for some unexplained reason, impels the insects 



Fig. 15. Locust — Melanophia hiviUatus Say — killed by a fungus. 

 (After Lugger.) 



affected with it to climb some tall weed or grass stem and cling to 

 it with such tenacity that the body remains long after death. The 

 spores given off from the fungus of the diseased or dead locust, are 

 more widely scattered by this peculiar habit which the host insect 

 has of climbing tall weeds, as they can the more readily be dispersed 

 over wide areas. 



Besides this fungous parasite other vegetable bacteria attack locusts 

 in favorable seasons. But this takes place only in long warm, damp 

 spells; during which the locust has sought shelter and been deprived 

 of food. Many are then often congregated together and one indi- 

 vidual affected by the disease may inoculate hundreds. In dry sea- 

 sons, the locusts and green grasshoppers are much more healthy and 

 abundant and the damage which the}' do is much greater than in a 

 wet season. 



