APniDID.E OF FORMOSA. 113 



Oenanilie stoJonifem : winged and wiugless forms iu lurge numbers ou 

 April 25, 1922, near Taiboku. 



Brachysiphoniella gramini Takali. 



(Host plant) 



Leerdu hexandra : only the upper sides of the lilades are attacked. 



(Season when the insect is coiumou) 



Near Taihoku this aphis is very common at any season tlinJiiglKnit the 

 year, occasionally occiuTiug iu large numbers. 



Near Tokyo it may lie seen on this Diersin from the begimiiug of August 

 to the last of Octolier, during which ^xaiod it is occasionally most aliundaut. 



(Winged Ti'S'ijxirous female) 



The winged forms occur at any season, liut are very reduced in numbers 

 near Taihoku. Near Tokyt> they appear from time to time during tl;e m(inths 

 of August, September and October, but are rather reduced iu numbers. 



(INLile and o^■ipill•ous female) 



In Formosa this species is always viviparous, without producing sexual 

 forms. 



(Intermediate) 



No intermediates have been oliserved. 



(Habit) 



It is very inacti\o and the wingless forms are sometimes submerged m 

 the water on the lAides of the host. 



(Distribution) 



Formosa : Taihoku, Kagi. Shiuka. 



Japan : Tokyo. 



Hyalopterus pruni (Fab.) 



A. Oljservations in Formosa. 



(Host plants) 



Phragmitcs comniv.nis : the upper sides of the bbides ;U'e atbu-ked. In 

 Formosa the viviparous females inhabit this plant at any season throughout 

 the year. 



