AniIDID.12 OF FOR\:OSA. 73 



Macrosiphiun debilis Tak:ili. 



Host plant. — Laduca drhHis, uttackiug tlie stem. 



Tliis apliis seem? to be rather rare, since the author has observed some 

 wingless viviparous females ou March 1 1 , wingless and winged individuals on 

 October 15, 1921, and some wingless forms on February 25, 1922, near 

 Taihoku. 



This aphis and Ainpliompliora dcraccce (v. d. Goot) are sometimes found 

 together. 



Macrosiphum paederiae Takah. 



(Host plant) 



P(erleria (omcnfosa : the leaves and the stems are attacked. The aphis 

 feeds only on this plant. 



(Season M'hen the aphis is abundant) 



The aphis is common, sometimes occurring in abundance in Formosa, as 

 well as, near Tokyo. 



(Winged viviparous female) 



Th? winged viviparous females are very common at any season in For- 

 mosa, but near Tokyo I have observed them only fi'om May to July. 



(Male and oviparous female) 



In Formosa this aphis is continuously viviparous even iu the winter, never 

 ]M-oducing sexual forms. Near Tokyo, however, the winged males and wingless 

 oviparous females make their appearance at the last of October. The females 

 outnumber the males as is common iu the Aphididie. The sexuparaj are not 

 provided with wings. 



(Intermediate) 



No intermediates have been observed. 



(Distribution) 



Formosa : Taihoku, Shirin, Bhinten, Kagi. 



Japan : ToAy(j, 



