86 
LEAFHOPPERS AFFECTING CEREALS, ETC. 
part of the month. While broods are not very definitely separated 
it would seem from the observations made that the first brood of 
nymphs occurs from May until the early part of June, the adults of this 
brood from the last week in May until the middle of July, and the 
second brood of nymphs from the last week in June until the first week 
in August, while the second brood 
of adults, beginning to appear about 
the middle of July, extends through 
August; a third brood of nymphs, 
appearing first about the middle of 
August, develops during August and 
September, and the third group of 
adults, beginning to appear in early 
September, survives on through 
October. From this life history it 
is obvious that it will be difficult to 
fix upon any time at which mowing 
of the grass would be distinctly 
effective in exterminating the spe- 
cies, consequently we must depend 
upon the direct treatment of hop- 
perdozers or sprays or the effect of 
general rotation of crops as the prin- 
cipal means of control. 
This species has been found to be 
quite extensively parasitized by the 
small hymenopterous parasites of 
At one time 
at Cedar Point, Ohio, as many as 
about 20 per cent of the individuals 
collected showed the presence of the little external sacks of these 
parasites. Doubtless they constitute an important factor in keeping 
the species reduced in numbers throughout its range. 
The Destructive Leafhopper. 
(Athysanus exitiosus Uhl.) 
Athysanus exitiosus was first given definite recognition as a destruc- 
tive pest in the report of Prof. J. H. Comstock for the Department of 
Agriculture, in 1879, and in connection with his report there is given 
a technical description of the species by Prof. Uhler. 
While it seems impossible that the injuries of the insect should 
have escaped previous observation, it is probable that they were 
referred to some other insect or that the insect itself was not con- 
nected definitely with this kind of injury. 
This report mentions damage during the previous winter to grain 
in western South Carolina, parts of North Carolina ; and Georgia, 
Fig. 20.— Say's leafhopper (Deltocephalus say 
Adult; b, face; c, vertex and pronotum; d, female the family DrVmidse 
genitalia; e, male genitalia; /, wing; ff, nymph 
All enlarged. (After Osborn and Ball.) 
