132 KYOirlU TAKAII.VSUI: 



Celtl.'i nervosa : the lower suvfncc of the leaves, especijiUy the yonug ones, 

 mill the distal pai-ts of the touder shoots are attacked. 



(Sejison when tlie apliis is alnuidant) 



Near Taihokii tliis apliis is very coiniuon, ofteu bomg most numerous in 

 ]May, Jiiiui and July, usually liccioiuiug scarcer from late summer ouward 

 tlu\)ughiiut llio \viiit«T. 



(WinnxMl viviparous female) 



The wingixl forms are very common at auy seasou except dm'ing wiuter 

 vhen they becoir.e so scarce that it is often qiiit(! difficult to find them. 



(]\Iale aud oviparous female) 



Ni!ar Taihokn, the leaves of the young Cdfis are gi-ecn even in the winter 

 aud the ajihis feetliug on such young hosts continues to produce the young 

 throughout the winter, without producing the sexual forms. However, the 

 leaves of the older CcUis begin to A\ither gi-adujdly aud from Nevember imtil 

 the last of February of the followiug yCiU' all the leaves are fallen ; the aphis 

 on these kvues becomes more scarce as the winter approaches, and does not 

 jwoduce oviparous forms, all tin; individuals (^viviparous females) vanishing on 

 the falling lea\es during the wiuter. However, a few winged males, which 

 soon die, without copulation, as no oviparous females are produced, s:)metimes 

 occur on sucji old trees in December. Thus the aphis is viviparous throughout 

 th{» year near Taiiioku. 



In the spring some winged forms migrate to the old ti-ees from the 

 young and new colonies are thus established there. 



(Tntermetliate) 



The intermediates are quite r.ire, onl}- erne brachypterous \ iviparous female 

 liaving been observed on .July 27, 1920, at Taihoku. The hooks on the hind 

 wings of this female were well developed. 



(Habit) 



This aphis is rather inacti\e, not dropping to the gi-ouud uor jumping 

 from the host wlu'U disturbe<l. AVhen at rest the head is often direct«l toward 

 the biise of the leaf. 



(Distribution) 



I'ormosa : Taihoku, Kagi. 



