TWO NEW SPECIES OF APHIDS PARASITIC 

 ON POPLAR IN HOKKAIDO 



BY 



Matsuji Hoki 



(With 2 TcNt Figures) 





In 1918 and 1919, Prof. Dr. S. Matsumura has described si.x species of 

 aphids parasitic on the poplar-tree in Hokkaido. Since that time, any species 

 of this group on the same host plant has not been reported up to the present. 

 In the course of the study on the Japanese insects, the writer found a few 

 species unrecorded on our poplar-trees. Among them, one species belonging to 

 the genus Melanoxanthduim seems to be a new to science, and another one 

 species does not belong to any one of the hitherto published genera. The 

 present paper was intended to report these two interesting species of aphids. 

 In this place, the writer wishes to express his heartiest thanks to Prof S. Matsu- 

 mura, and also indebted to Mr. S. Kuwayama for many valuable suggestions. 



Melanoxanthelium yexoense Hori, n. sp. (Fig. i, a-1) 



(Alate viviparous female) — General colour reddish brown. Antennae 

 black, except the basal half of joint III which is yellowish. Legs black, greater 

 part of the femora yellow. Abdomen with the six or seven transversal blackish 

 markings and the several black spots on the lateral side of the dorsum. Cor- 

 nicles pale yellow with the blackish apices. Body provided with many rather 

 long hairs. Head with the several long bristles, no prominent frontal tubercles. 

 Antennae stout, much shorter than body, imbricated, with numerous conspicu- 



[Transact. Sapporo Nat. Hist. Sc. XXV, Ft. 2, 1929.] 



