ArHIDID.E OF FORMOSA. ^43 



nana ou November 12 auil 21, 1920, U(':ir Tailioku. 



(Male and o\aparoiis female) 



Tliis apLis is coutiuuoiLsly vivip.iroiis tbrongliout tlio year near Taihoku, 

 tlie sexnales never having been found. 



(Intermediate) 



Xo intermediat.^s have been discovered. 



(Communal life) 



The wingless viviparous females ai'e sometimes found in the nests of 

 O/prifernv'S nitohci Sliiraki (Termitidae) built arouud the bases of the stalks of 

 B' I iiihuffa slcnodaclnj<(. 



(Habit) 



Tliis aphis is very inactive, gi'ouping rpito densely ou the Baiahusn, with 

 the hv-ad directed upwards. It has the habit, when distarlx'd, of elevating the 

 posterior pah of logs, not dropping to the gi'ound. 



(Disti-ibution) 



Formosa: Taihoku, Sjzan, Sliinteu, Taiuau. 



Oregma bambusifoliae Takah. 



(Host plants) 



Bamhma stenoslacluja, Bambusa nano, Bamhusa -sp., Dcadrocnhunm Jati- 

 florm : the lower sm-faces of the leaves are atticked. 



(Season when the insect is abundant) 



Tliis aphis is one of the most common species near Taihoku, where it is 

 most abundant in March and April, its numbers Vieiug sometimes gi'eatly 

 reduced fi'om June until Saptember, during wlucli period it is sometimes dif- 

 ficult to detect the aphis in the field when tlu' leaves of the host become very 

 hard. 



(^yinged viviparous femalej 



Numerous winged fjrms make their app.nirauce each year, near Taihoku, 

 fi-om the end of April until the beginning of June. In other months only tho 

 wingless forjus are seen. 



(Male and oviparous female) 



This aphis is continuously vi\ipar._)U3 all tlie year, near Taihoku. Tho 



