1-2-1 RYOICHI TAK.VHASUl: 



Tliis sjx'cR'S is quit*' rjire, .-i ffw win«;o<l vlvip.ivous femilos liavijig 1)ccn 

 olsorvitl oil tlio lower siirfjict! of tin? leiivcs ou M;in-li 5, 1921, ;uid M;uith 30, 

 1922, ne.iv Taihokii, ;uul on 'Mmrli 23, 1921, at IvwaiisliiiX'i, Formosa. 



Myzocallis kuricola (Mate.) 



(I'l. VT. A, fi.ns. 1—4) 



(Iloi-t plaut) 



CdsUinca viiJijarifi, Querciis scrrata, Q. viriulnUs, Q. sp. : tlio lower sui'fiices, 

 aloug the luiclribs, of the leaves are attacked. The young twigs are also 

 sniK-ti 11103 attacked. 



(8eiison whcu the insect is common) 



Tliis aphis is very comiiiou near Tokyo fconi abnit the middle of May to 

 the last of October, but its muubei'S are S)metimes greatly reductxl aliout July. 



(Wiuged viviparous female) 



.\11 the viviparous feiiiides are in-ovided -with >viugs, tlie wingltas? oues 

 having never Ik-cii discovered ;is iu other six!cies oi MifMolliis. 



(Sli\\Q and oviparous female) 



The wiuged males aud wingless ovip:ii\)as fiMiiaks, the latter outuumlKU'iug 

 the foi-mer, ap^xiar at tlie last of Ootolx;.-, near Tokyo. 



(Tutermediato) Se(^ ])latti VI, A, figs. 3 — 4. 



Among tlie winged viviiKuvius femaks there ju'e fonud two forms, the 

 mjicroptt rous aud the brachypteroas, which are almost m^yvA in uumlx^r or the 

 lattt'r sometimes outuumlK'ring the former. Tlio Ijrachypterous forms are proiluced 

 very commonly at any season as are the macroptcrous ones, Init tlK'ir thorax 

 are not well develo])ed, beiug provided with very short wiugs. 



It is a veiy remarkable fact, however, tliat the hooks on the hiinl wiugs 

 of the brachvptvroiis foruLS are ius \\ell develojx'd as are tli'jse of the macroptcrous 

 forius. Tht' males are m;K!ropterous. 



(Hiibit) 



The ajihis is rather iu;u:tive, grouping ratlur deiisi'ly along the midribs of 

 the lea VIS. The \iviparous females seci'ete wliit<> pjwders from tlie surface of 

 the dorsa. 



(Uisti-ibution) 



