108 
of this leaf-hopper is shown in figure 26 at 7, with wings spread as in 
life, while at } the same is illustrated with wings folded in the natural 
position which it assumes when feeding or at rest. From the nature 
of its markings this is a rather attractive species, and the yellow of 
the common form found in the District of Columbia is variegated 
above with green and bluish, forming stripes on the wing-covers, as 
shown. A young nymph or larva is illustrated at ¢, and d shows the 
nymph in the last or pupal stage just previous to molting. 
This species, as defined by Prof. E. D. Ball (Proc. Iowa Acad. Sei., : 
Vol. VIII, 1901, p. 30; Ser. 5, No. 21, Ohio St. Univ. Bul., p. 31)9ua% 
evidently more abundant in the South. Its name does not appear in 
any lists of New York or New Jersey species at present available, 
although it has been recorded from Ohio and Ilinois. It extends from 
central Mexico and the Gulf States northward to Maryland, Virginia, 
and the District of Columbia, and westward as far as Illinois. What 
are considered varieties of this species, however, have been described 
from South America and the Pacific coast. 
Asa result of the investigations of Messrs. Osborn and Ball (1. ¢.), 
some generalizations as to the life habits of these two families of leaf- 
hoppers have been drawn. The species under observation in Iowa 
showed, as a rule, a decided limitation as to the food plant, holding 
to one species while in the immature stage, but feeding more indis- 
criminately in more mature stages, in which respect these insects 
resemble larger forms of Hemiptera, such as the harlequin cabbage 
bug and squash bugs, which subsist normally on single orders of 
plants. The species observed deposit eges upon the stems under 
the leaf sheaths or in the leaves of the food plant. There is a wide 
divergence as regards life histories, some species producing one gen- — 
eration; the majority of the grass-feeding forms, which includes a 
very considerable percentage of these insects, two generations; and 
some having three in a season. Save in the case of hibernation in the 
adult stage, the life of a generation of adults does not exceed two 
months, while that of the individual rarely exceeds one. Males appear. 
a week or ten days earlier than the females, and their disappearance 
is much earlier. There is so little overlapping of generation that one of 
adults disappears before the nymphs of the next have matured, so that 
individuals observed at any time may be referred to the generation 
to which they belong. The eggs for each generation are deposited 
within a limited time, so that a period may be defined when all eggs 
of a given species will have been laid, and during which measures for 
their destruction may be applied. 
As a further result of these studies of the life economy of leaf- 
hoppers, it was ascertained that simply cutting the grass (and perhaps 
other plants affected) and leaving it in the field would prevent hatch- 
ing, as in no case did eggs observed hatch from stems that had been — 
