ArHIDID.E OF FORMOSA. IQl 



Jjip.an : Tokyo, etc. 



Aphis medicaginis Ivjcli. 



(Host plants in Formosa) 



Ficia favfi : this plant is one of the most favored hosts, and the aphis 

 sometimes •occm's in great abnndance on it about Feljrii.ary, doing serious 

 damage. 



As'ragalus si amis : a few wingless froms were observed on March 8, 1021, 

 near Taihoku. 



Gljicrae soja : the insect has never lieen observed in abundance on this 

 plant. 



WiJisfrocmia hulica : many winged and wingless forms wore observed on 

 May 30, 1920, ne.ar Taihoku, and on xlpril 30, 1922, at Tansui. 



Acschyncmcne indica : maiy vivipirous females, both winged and wingless, 

 were observed on July 13, November 20 and 30, 1920 ; and on Si'ptemver 

 21, 1921, near Taihukn. 



Pisum sp. : many winged and wiugless \'iviparous females were collec'.ed 

 on April 28, 1920, by Dr. Shirald in the islands of Boko. 

 (Season when the insect is abundant) 



Near Taihoku the greatest abundance see us sometimes to take place ou 

 I'icia Java about February. 



(Winged viviparous female) 



The winged forms are very common near Taihoku, as well as in .Jaiiiu. 

 (Male and o\iparous female) 



Tlie sexual f<.)rms are never produced in Foraiosa, being always vi\-iparoug 

 even in the winter. 

 (Distribution) 

 Fiirmosa : Taihoku. 

 Japan : Tokyo, etc. 



Aphis rumicis L. 



(H'-jst plants) 



Sulmnni viijriaii : tde under surfaces of the leaves are attacked and the 



