THE SHARP-HEADED GRAIN LEAFHOPPER. 15 



parasites upon jassids, but whether or not they have been reared 

 from this species the writer does not know. 



ENEMIES OTHER THAN PARASITES. 



It is a common sight to see jassids caught in spider webs. Several 

 adults and nymphs of D. mollipes have quite frequently been 

 observed in webs, and in more than one instance the writer has seen 

 spiders 1 carrying off dead adults. In Bulletin 108 of the Bureau of 

 Entomology is an account of Reditviolus ferus L. as a predaceous enemy 

 of leafhoppers. During the past summer the author observed on two 

 occasions the large agricultural ant {Pogonomyrmex harbatus Smith) 

 dragging off an adult grain jassid. Turkeys and toads have been 

 observed catching and eating the adults in alfalfa fields. Prof. 

 Osborn 2 gives a list of over 100 birds whose crops have been exam- 

 ined and found to contain jassids. 



FUNGUS. 



Prof. Osborn makes mention 3 of a fungus, Empusa grylli, which 



causes an epidemic disease affecting this species. The occurrence of 



this fungus has been recorded also by Prof. F. M. Webster and Prof. 



H. Garman. 



REMEDIAL MEASURES. 



From a study of the habits of this jassid certain simple preventive 

 measures present themselves. In the Salt River Valley of Arizona 

 and in localities of similar conditions the keeping down of wild 

 grasses, principally Johnson grass, along irrigation ditch banks, fence 

 rows, and along roadsides during the summer months will do much 

 in preventing the species from spreading and increasing in numbers. 

 By cutting down or grazing sheep upon these broad-leaved grasses, 

 which afford the preferred summer food, their summer breeding 

 places 'will be destroyed and an immediate check upon the species 

 produced. 



As soon as possible after the grains are harvested the ground should 

 be broken up and planted. If immediate planting is not practical, 

 then the ground should be broken again by cither replowing or har- 

 rowing after two or three weeks to keep down all native grasses and 

 weeds. 



Quoting from Osborn: "The direct treatment which has had the 

 mosl thorough trial is the use of the hopperdozer, which consists of a 

 sheet-iron strip coated with coal tar. The apparatus is drawn over 

 the grass and the insects, hopping at its approach, fall upon the sur- 

 face, and thus many are killed." 4 The hopperdozer can boused to 

 advantage while the grain is young and short. It should bo used 



■ A lift of spiders which teed upon leafhoppiT.. mi-, i." i»uii<i in Bulletin No. 108 of tho Bureau of 

 Entomology, U.S. Department of Agriculture, page 35. 



eft., p. r,~. 

 < Op. eit., p. 87. 



