148 EYOICni TAKAnASni: 



beiug fi^•all^• coiuoutctl to the leaf. Tlio youug nympbs, however, iire yellow 

 imd walk alwut (m the host phiut. Neiir Taihoku the leaves of the Quercus 

 serrata ofteu bogiu to gi-adiially wither at about Jauuarj', but the new leaves 

 begin to unfold duiiiig tlu; sauio luouth, aud the young uyiophs migi'ate to 

 til.,' now loiives fiv)iu the old ones at this season. 



(Hiibit) 



The nymphs of tlio winged form have the hal>it of gi'oupuig quite densely' 

 like some species of Orajm', ]n\t tlie wingless ones liiive no such halnt. The 

 iiymplis of the winged form of Ad'(jiyptcnjx fid Takah., unlike tlK)30 of A. 

 quercirohi, are rather sporadic. 



(Distribution) 



Formosii : Taihoku. 



Astegopteryx distyfoliae Takah. 



(Host jilauts) 



A. Winter iiost 



Difttylium raccMostdu : the loiives are attacked. Many small galls are 

 produced in the spring by the stem-mothers on the upper, as «ell as the 

 lower, surfaces of the leaves. 



1>. Sunuucn' hosts. 



Quercus ij/itn'luli/cra ; Q. dciilota : Q. crispuJa : Quercus sp : the lower 

 surfaces of the leaves are attiw^ked. This aphis is present on these Qv.ercl kom 

 about the middle of June until the last of November, producing no galls, aud 

 beuig most abundant in the fall when the sexiipar* are i>ru(luced. 



(Season when the species is cjmmou). 



Near Toky(j this apliis is quite lunuerous, although its luimbers are 

 reduced during the snmmtn'. 



(Winged viviparous female) 



nie feiujiies of the second generation aud the sexuparae are always pro\ided 

 \\ith wings, l)ut those of all other generations are always wingless. 



(^lale and ovipirous female) 



The males, as ^\ell as the oviparous females, have no wings, but possess 

 a ^\ell developed rostrum and leg=. Tliese forms are present in very large 

 Lumbers on the lower surface of the leaves of the D'tstijUum from November 



