WALNUT APHIDES IN CALIFORNIA. 7 
size; subcosta and wing insertions pale yellow; stigma pale gray, with a darker area 
at the confluence of the third discoidal vein, and another such though smaller area at 
the apex; veins rather heavy, dark brown, all three discoidals arising from the sub- 
costa and thickened at their bases; second branch of third discoidal nearer the wing 
apex than the first fork; third discoidal describing a regular gentle curve for its entire 
length; stigmatic vein entire, the depth of its curve varying in different examples, 
generally reaching the wing margin midway between the apex of the stigma and the 
the end of the third discoidal (often it touches the margin considerably nearer the 
stigma, but rarely nearer the third discoidal) . Legs rather short, but a little longer than 
those of the pupa; front pair yellow with the tarsi and apical third of the tibiae dusky 
Fig. 5.- 
■Chromaphis juglandicola: Winged viviparous female (appendages of left side removed). 
Left antenna; b, right cornicle; c, front tarsus. (Original.) 
gray and the knee spot rarely present (gray when present) ; middle pair yellow, with 
an indefinite gray spot on the upper side of the femur above the knee and with the 
tarsi dusky gray; hind pair yellow, with a coal-black spot (sometimes produced into 
an annulation) on the upper side of the femur above the knee joint and with the tarsi 
dusky gray as in the other paii-s. The knee spots are always present on the hind 
femora, while they occur in about 80 per cent of individuals on the middle femora. 
In 35 individuals examined throughout the year all had the spots on the hind femora, 
28 had spots on the middle femora, and only 1 had spots on the fore femora. Abdomen 
pale lemon-yellow, widest at segment 3, considerably wider than the thorax, gen- 
erally bearing two oval brown spots on segment 5 and more rarely with two similar but 
smaller spots on segment 4; occasionally immaculate. These spots are sometimes gray- 
ish, varying in intensity, and appear to be the pupal markings retained in the adult form. 
