DELTOCEPHALUS AFFINIS GILLETTE AND BALL. 83 
throughout the northern United States and southern Canada and is 
evidently a form that was reported by Dr. Wm. H. Ashmead under 
the name harrimani from Alaska (report of Homoptera, Harriman 
Alaska expedition). 
DESCRIPTION. 
The adult insect is of a light gray or brownish-gray, often pale, 
but varying so much in color that it has been many times de- 
scribed under different names. 
It is nearly one-sixth of an inch 
long and is to be separated from 
D inimicus by the absence of defi- 
nite black spots on the head and 
thorax and by the slightly smaller 
size. The head, too, is a little 
more distinctly pointed. (See fig. 
18.) The most positive characters 
are found in the genitalia, the last 
ventral segment of the female 
being short, nearly straight on 
the hind border, while the male 
valve is very much enlarged and 
convexly rounded, almost cover- 
ing the plates, the tips of which 
appear as slight projections be- 
yond its hind border. : 
The nymphs are of about the 
same form as those of inimicus, 
but differ distinctly in that the 
body is uniformly hight yellow Fic. 18.—Deliocephalus affinis: a, Adult; b, face; c, 
. ‘ vertex and pronotum; d, female genitalia; e, male 
without the black lateral border genitalia; /, wing;g,nymph. Allenlarged. (After 
which is characteristic of inimicus. Osborn and Ball.) 
The head is bluntly angled in front and in the later nymphal stage 
the wing-pads expand in a rather sharp angle back to the second 
abdominal segment. 
LIFE HISTORY. 
The life history of the species has not been determined with com- 
plete accuracy and is difficult to establish because of the irregularity 
with which the different generations appear and the overlapping of 
adult and nymphal stages. From observations in Towa it was believed 
that there might be three or possibly four generations each year and 
the designation of the broods so far as they could be determined 
showed adults from the middle of May until the last of June; nymphs 
