APIIIDIDJ3 OF FORMOSA. ^^.g 



Oregma lanigera (Zolmt.) 



(Host plants) 



SacoJiannii officinarina : i\\.v. luwcr sni'faccs of tlio leaves urc !itt;ick<'il, 

 sometimes sufierriug se^•e^■el3■, 



Miscantlnis spp. : the lower surSices of tlio leaves are attacked. 



I tiunsferred v\iuglcss viviparous females from the Miscant/im to tha 

 Saccharum or fi'om the Sacchamni to the Blisc^ntlivs, with very siieocssfiil 

 results. 



(Season wheu the insect is almudant) 



In FormcTSf this species is very common, occasionally occim'iuy in great 

 aV)nudauce at any season either on the 3Iiscantkus or on the SaccJiorinn. 



(Winged viviparous female) 



Tlie winged forms are produced fi'om time ki time thi'ooghout the year in 

 till" colonies feeding on the Saccharum, although rather scanty in number 

 They are very rare in thoso fijediug on the Bfiscauthus, however, h;iviug been 

 observed on this plant onlj- on INLiy 3, 1920, and on NiDvemljcr 1, 8, and M, 

 19-21, near Taihoku. 



(]\Lile and oviparous female) 



It is entirely viviparous all the year, without producing the sexual forms. 



(Intermediate) 



No inteiTuediates have bet'n observed. 



(Some notes on thi life history) 



The nymi^hal stage of the wingless form lasts for alioiit 10 days, but th;'t 

 of the winged form about tw(_) weeks, in Jul}-, near Tailioku. 



(CV>mmnaal life) 



This aphis and Apkw misrcmiki Takah. are rarelv" found grouping together 

 ou the Bliscardlius. 



(Habit) 



The young nymphs walk aliout on the host; but the wingless adults are 

 rather sedentary in habit, grouping ^ery denselv", with the head directed in 

 indefinite dkections. They have the habit, when very slightl.v, though n^t 

 sti'ongly, distiu'bed, of moving the alidomen fi'om side to side for a few times. 



(Distributidu) 



