THE YELLOW CLOVER APHIS. 



23 



WINGLESS VIVIPAROUS FEMALE. 

 (Fig. 12.) 



Gonoral color palo yollowish green, with dusky tubt^rculate areas 

 bearing capitate setae on the dorsum, arranged as described for the 

 stem-mother and as shown in figure 12. Both the tubercles and 

 capitate hairs (fig. 12, a) are more prominent in this fonn tliau in 

 the winged female. 



Ey(^s (hirk red. Antennae almost as long as the body; relative 

 lengths of segments as in other forms; segment III with 7 to 12, usu- 

 ally 9 or 10, oval sensoria in a row atid the usual distal ones on V and 

 base of VI; basal segments 

 pale, the remaining ones grad- 

 ually darkening toward the 

 tip. Beak scarcely reaching 

 coxae of second pair of legs. 

 Legs pale, excepting the 

 joints, which are dusky, and 

 the tarsi, which are black. 

 Cornicles (fig. 12, h) and 

 cauda as in winged female. 



Measurements (from speci- 

 mens mounted in balsam); 

 Length of body, average, 1 .60 

 mm.; width, average, 0.76 

 mm.; antenna, averages, seg- 

 ment I, 0.076 mm.; II, 0.053 ^^^^- l-— The yollow clover aphis: Wingless viviparous 

 • TTT n c;i7 TA'' female, much enlarged, a, Lateral capitate hair of same; 



mm.; lli, U.Ol/ mm.; iV, 6, comicle of same, o, 6, Grcatlv enlarged. (Original.) 



0.347 mm. ; V, 0.316 mm. ; VI 



base, 0.156 mm.; VI filament, 0.162 mm.; total, average, 1.627 mm.; 



cornicles, 0.062 mm.; cauda, 0.171 mm.; hind tarsus, 0.130 mm. 



WINGED MALE. 



(Fig. 13.) 



Wingless males unknown. Head and thorax light olive-green; 

 abdonKMi pale yellowish green, with rather conspicuous black mark- 

 ings. Shiiilar to the wnnged female but smaller, with more slender 

 body (the illustration, fig. 13, shows the abdomen too robust), and 

 the dusky tubercular areas on the dorsum of abdomen smaller. I lead 

 and thorax bearing a number of hairs in a more or less regular order 

 as shown in the illustration. As stated, the abdominal markings arc 

 reduced in comparison to those on other forms. The areas of the two 

 median rows are larger than those of the lateral rows, but they vary 



