Aphididae of Formosa. — 3. 79 



Brownish black (9) 



( 9 ) Horns on the head almost as long as the 1st antennal joint 



0. orientalis Takah. 



Horns almost as long as the 4t}i antennal joint. 0. oplismeni n. sp. 



Oregma panicola Takah. 



Aphididae of Formosa-l, p. 5 (1921); Aphididae of Formosa-2, pp. 49 and 

 144(1923). 



^ull-gro^\•n nymph of winged viviparous female. 



Head and prothorax fused together, provided with numerous very small wax- 

 pores, wliich are rather irregular in shape like those of Orejma hamhusicola 

 Takah., scattered over the wliole surface of the dorsum. Head furnished with a 

 few hairs which are almost as long as the horn. Horns rather stout, but much 

 more slender than the antenna, a little shorter than the first antennal joint, the tips 

 rounded. Antennae stout, more so thin tlie tilaao, S-jointed, provided witli a few 

 long bristles; the 4th joint sliorter thaji the basal two joints taken togetlier, witli a 

 very small apical sensorium which is somewhat protuberant, the 5th not imbricated; 

 the relative length of joints as follows: III-32, IV-14, V-25. Eyes not protruding, 

 with the ocular tubercles (3 facets) somewhat protuberant. Rostrum stout, not reaching 

 the middle coxae. Dorsal and lateral tubercles absent. Wing-pads wide. Abdo- 

 men without wax-pores but with a few bristles. Cornicles very short, much wider 

 than long, expanded toward the base. Cauda very short and wide. Anal plate not 

 bilobed. Hind femora almost as long as the antenna, provided with some moder- 

 ately long bristles; tibiae furnished with some very long bristles; hind tarsi scarcely 

 imbricated, almost as long as the 3rd antennal joint, with a few very long bristles. 

 Tjcngth of body-about 1.7 mm. Antenna-about 0.5 mm. 



Nymph of wingless female provided with many circular wax-pores distributed 

 as in the wingless adult. 



Numerous viviparous females, botli winged and wingless, were observed on 

 Panicum patens on December 3, 1922, at Urai, Formosa. Many wingless females 

 were collected on the host on November 22, 1923, at Kankau, Koshun, Formosa. 



Oregma bambusicola Takah. 



Aphididae of Formosa-l, p. 89 (1821) and ibid.-2, pp. .50 and 142 (1923). 

 Nymph of viviparous female. 



i The first instar Dark brownish purple. Horns yellowish brown. Eyes 

 black. Antennae yellowish brown, with the apical parts blackish. Legs yellowish 

 brown. 



