ArHIDID.-E OF FORMOSA. J^y 



nutil about the iOtli ilay ol March of tlie following year. 



(Life Liitory near Tokyo) 



The galls start about April, attaining their full growth and devcloprLont 

 toward the end of May, and there is only one steni-mother in each gall. 



The stem-mi-ithers, which are, of course, wingless, begin t> produce the 

 young about the middle of May. The adults of the second generation, which 

 are \\iuged, make their appearance about the liegiuniug of June and migrate 

 t) the Qwrcus, leaving the galls on the D'lshjlUim. The females of the tliird 

 and the succeeding generations on the summer hosts arc eutu'ely wingless, 

 black in colour, aud aleurodiform, being firmly cemented to the leaf. The 

 sexupara?, which are winged, occur at about the beginning of Novemlwr and 

 return to the winter host to produce the sexuales on the lower surface of tin; 

 leaves. The males are not rare. The eggs are yello'wish green in colom", not 

 changing ts black, and are placed upon the lower surfaces of tbe leaves of the 

 Dislylium. 



(Distribution) 



Japan : Tokyo. 



Astegopteryx cuspidatge (Essig et Kuw.) 



(Host plants) 



Qiicrcus dentnii. : Q. vuspi'Iafa : the young shoots and branches are 

 attacked. This aphis spends the whole life cycle on the Quercu.% without 

 producing galls. Some wingless viviparous females are sometimes observed in 

 the cre^"ic«s of the bark on the stems. 



(Season when the insect is common) 



Near Tokyo tliis aphis is very common at all seasons, sometimes occumng 

 in large numbers. 



(Wmged viviparous female) 



Many winged forms appear only in Miy aud June. 



(Male and oviparous female) 



No sexes occur near Tok,\-o, the species Ijeing viviparous even in the 

 vv'iuter. 



(Intermediate) 



Nj intermediates have Ijeim observed. 



