GO 



KVOICIII TAKAH.VSJII: 



"Winged \i\ip:a'ou3 femalo. 



IIcjul, eyes, laesotliovax, cornicles unci canda black. Antenna} black, paler 

 at tlje ba^e of the Srd joint. ProtLorax aud abdomen l)lackish gi-eeu. Legs 

 aliucst black, paler at the bixses of the fore femora. Wings hyaline; stigma 

 aud veins gray. Head provided ■with some rather long fine hairs. Antermro 

 stout, imbricated, pro\ided with some long fine hairs ; the 13rd joint provided 

 ^\■ith 26 —30 largo or small circular seusorifi scattered over the whole length ; 

 tlio 4tli witli 12 — 14, the 5tli 15, similar seusoria ; the relative length of joints 

 .•IS follows : m— 3o, IV— 26, Y— 23, VI— 50 (13 |-37). Kostran reaching 

 tlio middle coxic. Prothorax with a large, stout, bhmt lateral tulxircle, abdomen 

 with 5 similar, but smaller, tubercles ou ejich side, those on the 1st segment 

 largest. Wing-veins normal ; hind wings with 2 almost pandlel obliques ; 

 li(X)klets 4. Cornicles cylindrical, slender, shorter tliau those of the wingless 

 lonn, almost as lc:)ng as the s])ur of the last autennal joint. 



Length of body^2.5 mm. Antenna — 1.6 mm. 



Fore wing — 2.8 mm. Cornicle — 0.45 mm. 



Hosts. — S'-Onbucus raccmosa ; Sunihucui thunhenjiamt. 



Distiiljution. — Japan : Tokyi) ; Sapporo. 

 lOunjjxj ; North America. 



In Aphis samhuci, the winged forms usually appear in the 2nd, 3id, 4th 

 and otli generations and the sexupariC, the males being also winged. As is 

 well known, almost all aphids occasionally show same abnormality of wing- 

 venation. Jn hiv experience with this species the abnormal forms occur in 

 about 16 per cent in the wild specimens of the 2nd generation, iu 75 per 

 cent ill the sexupanr, etc. The data concerning these points axe given in the 

 follo\\ iug L-ible : 



