76 LEAFHOPPERS AFEECTIXG CEEEALS. ETC. 
Iowa Agricultural Experiment Station. The eggs are deposited in 
the leaf or stem, especially beneath the epidermis of bluegrass, and 
cause very minute, blisterlike swellings. These, for the winter 
generation, remain until spring and hatch, for the latitude of Iowa, 
in the latter part of April and early May, there being some variation 
according to season. This generation matures by the latter part of 
June or early in July and adults occurring early hi July deposit eggs 
which hatch within a few days, producing nymphs of the second brood 
in the latter part of July. These mature by the latter part of August, 
and adults are usually encountered from this time on until winter, 
although scattering nymphs are likely to occur during the autumn 
months. Xo proof, however, is available of a definite third brood 
for the season, and eggs deposited by adults in autumn survive the 
whiter to renew the cycle the folio whig year. 
During the growth of the nymphs five distinct stages have been 
observed, the first of which, the newly hatched nymph, is rather 
short, with a very prominent head and a small abdomen, and without 
clear markings. The second stage differs hi a more elongate form of 
body and a definite black border along the sides of the thorax and 
abdomen. The third stage differs from the second only in the 
appearance of the whig-pads, and from this stage on through the 
fourth and fifth stages the change consists merely in a greater 
intensity in coloring and relative increase in size of the wing-pads. 
At the end of the tibia of the hind legs there is a peculiar microscopic 
spatulate structure that occurs hi varying numbers from the newly 
hatched nymph to the adult form. In the specimens studied and 
figured there were for the first histar one. for the second instar two, 
for the third histar three, for the fourth histar five, and for the adult 
insect five. The adults are gray, with dark brown or blackish mark- 
ings. A very constant feature is the presence of three pairs of black 
spots, one on the vertex, one on the pronotum. and one on the scutel- 
luni. The length is about one-fourth of an inch. 
The molts occur at intervals of seven or eight days in examples 
obserA'ed in rearing cages and hi some instances the development 
from the newly hatched nymph to the adult occurred hi 32 days. 
The time of incubation for some eggs has been determined as not 
longer than 17 nor less than 10 days. This, however, was confined 
to jars, and it is possible that under outdoor conditions the rate of 
development may be more rapid. A record by Prof. "Webster of 
observations on the development of the species adds some further 
hiformation and may be introduced here for comparison. 
Several years ago, on November 11, a number of adults were placed on young wheat 
plants that had been reared indoors, and hence were free from affection by insect 
attack. The females began at once to oviposit in the tissue of the leaves, and the 
young could be observed developing within the eggs, especially after they had become 
well advanced. Young were especially noticeable just prior to their emerging by their 
eyes being jet black. The young molted a few days after hatching, and, so far as I 
