LEAF HOPPERS INJURIOUS TO CEREAL AND FORAGE CROPS 17 



is very sharply painted, of a yellowish-green color, and is marked by 

 several very delicate oblique lines. Beneath, it is nearly black, the legs 

 greenish, the wings a nearly transparent milky white. The female is 

 about one-third of an inch and the male about one-fourth of an inch 

 long. 



LIFE HISTORY 



It is rather curious, considering the great abundance and wide dis- 

 tribution of the species, that a full description of the nymphal stages 

 has not been published. This may be due in part to the very great 

 abundance of the species, or it may be because the nymphs, while 

 presenting evident characters, are not particularly striking in ap- 

 pearance; and partly, perhaps, it is due to the general neglect of 

 life-history studies for this group of insects. Egg deposition occurs 

 in the fall and is at this time mainly confined to large-stemmed 

 grasses growing in low ground or thoroughly moist locations, a selec- 

 tion which may be due to the more succulent character of such plants 

 at this time or to a preference for the larger stems. Oviposition in 

 midsummer appears to be less restricted, and apparently the eggs are 

 placed in the borders of the leaves as well as between the leaf sheath 

 and stem. A series of eggs collected by R. A. Vickery, at Salisbury, 

 N. C.j which quite certainly belong to this species, were placed be- 

 neath the epidermis along the margin of the leaf, the inner end of 

 the egg extending to the midrib. Owing to parasitism, these eggs 

 did not hatch, and the determination of the species is not absolute. 

 Mr. Vickery, however, secured egg deposition in a leaf of corn when 

 the insect was confined with this plant. 



The newly hatched nymphs have not been observed, but nymphs 

 of later stages have the characteristic shape of the adult, the head is 

 sharply pointed, a little less so in the early stages, and becoming a 

 little more acute with each of the molts. They are of light-green or 

 yellowish color, with four dorsal parallel stripes running very nearly 

 from the front of the head to the end of the body. These stripes 

 diminish gradually toward the end of the body, the two outer ones 

 disappearing at the middle of the abdomen, whereas the two central 

 ones continue to the end. The different molts agree quite closely in 

 appearance, except in the development of the wing pads. These in 

 the last nymphal stages form angles extending to the back of the 

 second abdominal segment. 



There are clearly two distinct generations annually and a some- 

 what irregular occurrence of different stages during the fall and 

 winter owing to the survival of nymphs and adults. Hibernation 

 seems to occur in all stages from the egg to the adult, although the 

 great majority must pass the winter in the egg stage. Eggs hatch- 

 ing in the spring give rise to nymphs which reach maturity by the 

 latter part of June, and these adults survive until about August 20. 

 The second generation of nymphs begins to appear about the second 

 week in August, and nymphs are found through September, October, 

 and November, although some individuals may become adult by the 

 middle of September and others remain as nymphs until winter. 

 These dates will vary somewhat with latitude, and possibly a greater 

 number of generations may be found in the South, but no positive 

 observations are on record for that region. 



129811—32 3 



