84 K. Takaliaslii 



Host.-Bmnbusa tmna, Bamhusa stenostacki/a, Bambusa, specie.s, attackiug the 

 lower side, especially tlie basal part, of tlu^ loaf. 



Distribution.-Formosa: Tailioku, Shiriu, Hori. 



The nymphs of the wingless form are provided with well-developed wax-pores 

 distributed as in the adults, with the anal plate not bilobed and the cauda not 

 constricted as in the adults of Ceratoglyphrna. The young nympliS iiave very 

 long, slender, sharply pointed horns on the head as in 0. haonhusicola Takah. This 

 new Oreqma closely resembles 0. montane v. d. Goot, but differs from it in tlie 

 following characters : 



(1) Winglers form never yellowish in the nymphal or adult stage. 



(2) Wingless form provided with wax-pores on the head. 



(3) The 3rd antennal joint of tlie wingless form almost as long as the 

 4th. 



(4) Winged adult with tlie horns on tlio head almost lacking. 



Since the publication of the results of my observations on the species (Aphi- 

 didae of rormosa-2, p. 144), some wingless and a winged viviparous females have 

 been collected in October and November near Taihoku. 



Oregma koshunensis n. sp. 



(Pl.X,B,fig.8) 

 Wingless viviparous female. 



Almost black, slightly covered with powder and with a sliglit purplish tinge. 

 Antennae and legs almost yellowish brown. Body oval, not depressed. Head 

 fused with the protliorax, with some rather long hairs. Eyes composed of 3 facets. 

 Horns stout, broadest at the base, tapering, with the apex sliarply pointed, curved 

 upward, longer than the 1st antennal joint, somewhat sliorter than the 4tli antennal 

 joint. Antennae very short, rather stout, 4-jointed, with a few long hairs; tho let 

 joint much stouter than the 2nd; the 3rd narrowed on the basal portion, with the 

 apical sensoriura very small; tlie 4th almost as long as the 1st and 2nd takea toge- 

 ther; the relative length of joints about as follows : III-28, IV-20. Rostrum very 

 stout, nearly reaching the middle coxae. Al)domen with some rather long hairs on 

 the doi-sum. Cornicles not large, somewiiat protiilierant, not situated on hairy cones, 

 with the apex as large as or a little larger in diameter tlian the wax-pore on the 

 dorsum of the abdomen. Cauda much wider than long, the cornicle and the lobe of 

 the anal plate, constricted at the base, with some very long bristles. Anal plate 

 deeply lilobcd, with some very long bristles. Legs rather stout; tibiae much stouter 



