WALNUT APHIDES IN CALIFORNIA. 



15 



Fig. 6. 



ChromapMs juglandicola: Oviparous 

 female, penultimate instar. (Original.) 



or dusky gray legs and antennae. The oviparous or sexual female 

 molts four times but does not differ in appearance from the viviparous 

 form until the third molt is passed. 



THE OVIPAROUS FEMALE, AFTER THE THIRD MOLT (FIG. 6). 



Rather smaller and narrower than the full-grown form. General color pale gamboge- 

 yellow, sometimes lemon yellow. Body twice 

 as long as wide. Eyes bright red. Head with 

 six erect, capitate spines on the anterior margin. 

 Antennae short, reaching barely to the middle of 

 the mesothorax; 7-jointed, joint III the longest, 

 joints IV and V subequal, joint VI longer than 

 its spur or filament. Spur dusky, rest of anten- 

 nae pale lemon yellow. Head, thorax, and ab- 

 domen with two longitudinal rows of oval black 

 spots on the dorsum. Thorax and abdominal 

 segments 1-5 with two lateral longitudinal rows 

 of circular black spots, on which are situated 

 small tubercles bearing capitate hairs. Such 

 tubercles also occur on the black dorsal spots. 

 Eighth segment of the abdomen unmarked, 

 bearing on its posterior margin a fringe of six 

 capitate hairs. Legs pale greenish-yellow with 

 the characteristic knee spot on the hind femora 

 only; tarsi gray. Cornicles on the sixth segment, quite small, wider than long, pale 

 lemon-yellow. Cauda equal in length to the hind tarsus, pale yellow, rounded. Beak 

 very pale, almost white, reaching to the anterior coxae. Measurements: Length of 



body, 1.51 mm.; width of body, 0.76 

 mm.; antennae, joint I, 0.063 mm.; 

 joint II, 0.048 mm.; joint III, 0.136 

 mm.; joint IV, 0.083 mm.; joint V, 

 0.085 mm.; joint VI, 0.086 mm.; fila- 

 ment, 0.021 mm. 



Described from specimens 

 collected at Walnut Creek, CaJ., 

 and San Jose, Cal., October 16 

 to 26, 1912. 



THE OVIPAROUS FEMALE, ADULT STAGE 

 (FIG. 7). 



General color gamboge, varying in 

 newly molted examples to lemon yel- 

 low and in older individuals to salmon 

 pink or with a distinct brownish tint. 

 Eyes crimson. Head and prothorax 

 with indefinite dusky brown markings. 

 Ocular tubercles small . Anterior mar- 

 gin of the head with six capitate hairs 

 projecting forward. Thorax mottled all over with shades of brown, its lateral margins 

 lighter. Prothorax with two capitate hairs on either side of its posterior portion. Ab- 

 domen with two or three hairs on the lateral margins of each segment. Segments 4 and 

 5 and posterior half of 3 with dark brown or black markings which generally coalesce to 



Fig. 7. — Chromaphis juglandicola: Oviparous female. 

 Right antenna. (Original.) 



