Walnut aphids in California . er than long. Cauda globular, bearinga fringe of weak hairs, about equal in length to the hind tarsi, concolorous with theabdomen. Genital plates armed with weak hairs, pale yellow. Beak pale yellow,its extreme tip brown, extending halfway between first and second coxae. Measure- 32 BULLETIX 100, U. S. DEPARTMENT OF AGRICULTURE. ments: Length of body (average), mm.; width of body (average), mm.;wing expanse (average), mm.; antenna, joint I, mm.; joint II, mm.;joint III, mm.; joint IV, mm.; joint V, mm.; joint VI, mm
Walnut aphids in California . er than long. Cauda globular, bearinga fringe of weak hairs, about equal in length to the hind tarsi, concolorous with theabdomen. Genital plates armed with weak hairs, pale yellow. Beak pale yellow,its extreme tip brown, extending halfway between first and second coxae. Measure- 32 BULLETIX 100, U. S. DEPARTMENT OF AGRICULTURE. ments: Length of body (average), mm.; width of body (average), mm.;wing expanse (average), mm.; antenna, joint I, mm.; joint II, mm.;joint III, mm.; joint IV, mm.; joint V, mm.; joint VI, mm.;filament, mm.; cauda, mm.; Cornicles, mm. Described from numerous specimens, Walnut Creek, Cal.; October,1912. The Oviparous Forms. the oviparous female (fig. 16). Wingless. General color pale lemon-yellow, in mature individuals the central partof the abdomen diffused with orange. Body elliptical, *widest at the third abdominalsegment. Antennae half as long as the body, not on frontal tubercles, pale, with. Fig. 16.—Monellia caryella: Oviparous female. (Original.) an apical black ring on joints III to VI, inclusive; joints I, II, and filament dusky;joint IIT longest; joints IV and V subequal and each about four-fifths as long as jointIII; filament a little shorter than VI; VI about four-fifths as long as V. Eyes pale yellow; tarsi dusky. Hind tibiae slightly thickened. Cornicles verysmall, pale. Cauda pale, globular, beset with a fringe of weak hairs, not as long asthe hind tarsi. Thorax and abdomen with six longitudinal rows of capitate bristles,each surmounting a pale tubercle. Penultimate segment of the abdomen encirclednear its posterior margin with a fringe of weak hairs. Eight capitate spines on the WALNUT APHIDES IN CALIFORNIA. 33 head and six on the prothorax. Tibiae armed with a row of short bristles on theirinner margins. Beak pale, the extreme tip dusky, extending a little beyond theanterior coxae. The young oviparous female is enti
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