Aphididae of Formosa. — 4. 29 



Many apterous and a winged viviparous females were collected by the 

 author on May 16, 1924. 



Genus Greenidea 

 Key to Formosan species 



( 1 ) Caudal segment without a process (2) 



— : Caudal segment with a process ( 6 ) 



( 2 ) Nymphs white G. sp. 



Nymphs not white ( 3 ) 



( 3 ) The 3rd antennal joint of the winged form stout, provided with 



20-25 not circular sensoria often not arranged in a single row 



G. taiwana Takah. 



The 3rd joint slender, provided with 10-23 circular sensoria arranged 



in a single row ( 4 ) 



( 4 ) Cornicles very long, almost as long as the body.. .G. tenuicarpus Okaj. 



Body smaller. Cornicles not so long (5) 



( 5 ) Sensoria on the 3rd antennal joint distributed over the whole length. 



G. tattakana d. sp. 



Sensoria on the 3rd antennal joint not distributed on the distal 



portion G. nigrofasciataM&)s.i. 



( 6 ) The 3rd antenna] joint of the winged form provided with about 30 



or more, not circular, sensoiia not arranged in a single row ( 7 ) 



The 3rd antennal joint with fewer cicular sensoria arranged in a 



single r< >w ( 8 ) 



(7) The 3rd joint with about 55 sensoria G. mushana n. sp. 



The 3rd joint with about 30 sensoria. Body smaller 



(i ' . formosana Maki. 



( 8 ) The distal parr of the 6th antennal joint very slightly longer than 



the 3rd G. mangiferae n- sp. 



The distal part shorter than the 3rd (9 ) 



The distal part much longer than the 3rd (10) 



(9) Body black G. nigra Maki. 



Dark brown G. lcuwanai I'erg. 



(10) Apterous form greenish (11) 



Apterous form brownish G. ficicola Takah. 



