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 Reduviolusferus L. as a predaceous enemy 
of leaf hoppers. During the past summer the author observed on two 
occasions the large agricultural ant (Pogonomyrmex barbatus 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 
hi 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 either 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 
most 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 be used to 
advantage while the grain is young and short. It should be used 
1 A list of spiders which feed upon leafhoppers may be found in Bulletin No. 108 of the Bureau of 
Entomology, U. S. Department of Agriculture, page 35. 
2 Op. cit.,p. 28-31. 
3 Op. cit., p. 57. 
4 Op. cit., p. 37. 
