APHIDID^ OF FORIIIISA. g I 



Myzus tropicalis Tak.di. 



Host plant. — Pruuiis pcrstcu. 



The lower surfaces of the leaves are attacked and the iufested leaves are 

 rolled. 



Tliis aphis is very commou at Sozau, near Taihoku, where the aiithr>r 

 has observed the wiugless and wioge 1 viviparous females on April 10 and 

 the wingless one^ odI^- on June 17, September 25, and December 29, 1921. 

 Many wingle.ss ones were oliserved on the host on April 30, 1922, at Tausui. 

 Formosa. 



Myzus sasakii Mats. 



Host plant. — Prvniis psevdo-ccrasvs. 



The wingless viviparous females of the first generation (stem-mothers) 

 produce conspicuous galls along the ril)3 of the leaves (on the upjier svu-face) 

 of the host tree. The galls start about the middle of April, attaining their 

 full gi'owth and development toward the middle of May. lu everv gall there 

 is one stem-mother. 



The 2ud generation consists entirely of winged viviparous females which 

 leave the Frv.nvs about the middle of May and fly away iu search of the 

 summer host, which is as yet unkuowu. The stem-mothers are veiy inactive, 

 being provided with very small eyes and very sluiirt antennae aud cijrnicles. 



Distribution. — Japan : Tokyo. 



Myzus sakurae Mats. 



Host plant. — Priniv.s psrvdo-ainsus. The under surfaces of the young 

 leavers are attacked aud the iufested leaves are rolled. 



Near Tokyo the wingless viviparous females are pre.sent from about June 

 to the hist of September, during \\luch ^jeriod the winged \-i\-iparous females 

 make their appearance rather commonly. This aphis aud 3L/~i'-i pcrsic'e 

 (Suly.) are sometimes found in groups near Tokv-o. Not atteudeil by 

 ants. 



