﻿12« ÄA 學雜誌 第 参 卷第參 號 



SYNOPSIS OF THE ECONOMIC SYRPHIDAE 

 OF JAPAN (Pt. III). 



BY 



Porf. S. Matsumura, f.e.s. jap. 

 and J. Adachi, F.E.S. jap. 



IschiodoD Sack. 

 Sack— Ent. Mitteil 1 1. p. 5 (1913). 

 Body as that of Syrphus, with a narrow, lineal abdomen. Thorax 

 above on the lateral sides with yellow stripes and beneath with 

 some yellowish spots. Hind trochrnter of the male with a conical 

 projection. Abdomen nearly as that of Episyrphus cinctellus 

 Zett. 



Genotype ― Ischiodon trochanterica Sack. 



1. Ischiodon boninensia Mats. (n. sp.) PI. I, fig. i, o. 



§ Aeneous black, with very short yellowish hairs. Face pale 

 yellow, with very short whitish hairs. Vertex black, in the middle 

 of the front with a narrow black stripe, which becoming broader 

 towards the antennal basis. Antennae orangey ellovv, the ist and 

 2nd joints on the backs somewhat infuscated. Proboscis dark 

 brown, at the apex yellowish brown. Thorax on each lateral side 

 with a pale yellowish logitudinal stripe, which not reaching to the 

 scutellum yellow, in the middle with a fuscous spot, yellowish 

 pubescent. Wings hyaline, veins brown to fuscous, stigma fulvous. 



Calypteres whitish, halte res yellowish. Meso- and sternopleura 

 grayish white, with some silvers. Abdomen with 3 yellowish bands 

 that of the 2nd joint being narrowly interrupted, the hind margins 

 of the 3rd, 4th 5th segments narrowly yellow, the 4th on each side 

 with a triangular yellow spot ； venter yellowish, the 2nd, 3rd and 

 4th segments each with a black transverse spot, covered with a 

 few short fuscous and yellowish hairs. Legs yellyw, coxae, the 

 middle part of the hind tibia and a spot near the tip of the hind 

 femur, fuscous. 



