Walnut aphids in California . .87 mm. (average); width, mm. (average max-imum); antenna, joint I, mm.; joint II, mm.; joint III, mm.; joint IV, ; joint V, mm.; joint VI, mm.;filament, mm. Cornicles, mm. The stem-mothers pass through thepupal molt about one week before the finalmolt takes place, and after the latter theyacquire their full development as wingedadults. In the latter generations thepupal instar occupies from three to sixdays. THE WINGED VIVIPAROUS FEMALE (PIG. 5). General color pale lemon-yellow; many individ-uals are darker yel
Walnut aphids in California . .87 mm. (average); width, mm. (average max-imum); antenna, joint I, mm.; joint II, mm.; joint III, mm.; joint IV, ; joint V, mm.; joint VI, mm.;filament, mm. Cornicles, mm. The stem-mothers pass through thepupal molt about one week before the finalmolt takes place, and after the latter theyacquire their full development as wingedadults. In the latter generations thepupal instar occupies from three to sixdays. THE WINGED VIVIPAROUS FEMALE (PIG. 5). General color pale lemon-yellow; many individ-uals are darker yellow, yellowish-brown, or salmon-pink. Antennae on very small frontal tubercles, about one-half the lengthof the body, yellow, with the inner lateral margins of the first two joints dusky;articulations of joints III to VI and the whole filament dusky to black. Eyes present. Prothorax yellow. Thoracic lobes and scutellum light brown, some-times greenish-yellow, pale yellow in newly-molted individuals. Wings of medium. Fig. 4.— Chromaphis juglandicola:Pupa of winged viviparous fe-male. (Original.) WALNUT APHIDES IN CALIFORNIA. 7 size; subcosta and wing insertions pale yellow; stigma pale gray, with a darker areaat the confluence of the third discoidal vein, and another such though smaller area atthe 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 wingapex than the first fork; third discoidal describing a regular gentle curve for its entirelength; 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 thethe end of the third discoidal (often it touches the margin considerably nearer thestigma, but rarely nearer the third discoidal). Legs rather short, but a little longer thanthose of the pupa; front pair yellow with the tarsi and apical third of the tibiae dusky
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Keywords: ., bookcentury1900, bookdecade1910, bookidwalnutaphidsinca100davi
