i:].^. KYOICIII TAK.UI.VSIII: 



Periphyllus formosanus T.iknh. 



Ilo.st plant. — Acisr sj). : tlio lo\\er sides uf the leaves are attacked. 



A few V ingless vhipiroirs female?, wliich were probably the stem-mother.?, 

 and many winged one-; and their nymphs were ob.served at Suzau, near 

 Taihokn, on rebniaiT l-'i, 1921, and a feu winged and wingless forms on the 

 same plan', on I-'ebriLaiy 27, but (mly llie dimorphs margined with many 

 lamella' were found on June 12. 



The life histories of rcrijj/ii/livs uceri/olicE Takah., P. Javlrevlerice TaLih., 

 aiil P. j'npmica (Kssig et Kiiw.) were given in detail in tlie Zool. Mag. (The 

 ]),.bntsugaka-Za.sshi) Tokyo, vol. xxxi, No. 372. pp. 323—329 {^Wld}. 



Dilachiius piuiformosanus Takah. 



.Vphidida' of Formosa.— 1, p. .S2 (19211 



(Host plants) 



Pimw spp : the distal parts of the twigs and tlie young shoots are 

 att!ioke<l. 



(Season when the insect is connuon) 



Near Tiiilioku this aphis may be seen in very small numliers at any 

 seas )n, but is most comm-jn on the young shoots aliont the 20th day of 

 Ap'.il. I have never obsjrve<l it in abundance. Near Tokyc>, it is scarce 

 tlnonghout the year, as in Formosa. 



(AV'inged vi\iparou3 female) 



Tlie winged forms are extremeh" rare, but they seem to occur during any 

 month, since I have observed them in February, Jlay, September and Novemlier, 

 near Taihokn. 



i^Iale and oviparous female) 



It is viviparous throughout the ^ear, not jjrodiicing tiie sexnales near 

 Tailioku, nor near Tokyo. 



(Intermediate) 



No intermediates have been noticed. 



(Habit) 



The aphis is rather active, not grouping denseh', and directs the head 

 downwards when at rest. 



