33 



NEW ETHIOPIAN FRUIT-FLIES OF THE GENUS DACUS. 



By Prof. M. Bezzi. 



Since the publication of my previous paper on the Ethiopian fruit-flies of the 

 genus Dacus* I have received some additional species, the descriptions of which 

 are given in the following pages, with the purpose of completing our knowledge 

 of this very important genus of Diptera. For the material here illustrated I am 

 indebted to Dr. Guy A. K. Marshall, Director of the Imperial Bureau of Entomology, 

 and to Dr. Alberto Mochi, of Ghinda, Erythraea : to whom I have to offer my best 

 thanks. 



I. Subgenus Tridacus, Bezzi, 1915. 



1. Tridacus d'emmerezi, sp. nov. (fig. 1). 



Very distinct from any other known species of the present group, on account 

 of the broad fuscous patch on the middle of wings, around the small cross-vein. 



(J $. Length of body, 7-9 mm. ; length of wing, 6-7 mm. 



Body of a uniform reddish colour, with less striking yellow and brown markings ; 

 thorax and abdomen with short yellowish pubescence on the disk ; all the bristles 

 of head and thorax black. Head of a more yellowish colour, opaque, but shining 

 on the occiput, which has a paler border near the eyes ; ocellar dot dark brown, 

 on a brown transverse band ; frons with a less developed fuscous middle spot, 

 with almost indistinct dark dots on the sides and with two pairs of lower fronto- 

 orbital bristles, which are not approximated ; lunula reddish brown, shining ; 

 face with shining antennal grooves, in the middle of which are placed the very 

 small and rounded black spots ; peristomial spot dark brown. Antennae much 

 elongated, with the first joint about as long as the second ; they are entirely 

 reddish, the third joint being sometimes a little infuscated at the distal end ; 

 palpi very broad, pale yellowish, almost bare. Thorax with some irregular, 

 blackish markings on the disk, forming two more or less distinct longitudinal 

 stripes, which do not reach the scutellum, or two less distinct broader interrupted 

 stripes along the dorsocentral lines. Yellow markings as follows : humeral calli 

 entirely ; a narrow stripe along the transverse suture, broadly interrupted in the 

 middle, and continued on the pleurae with the broader mesopleural band, which 

 ends with a small spot on the upper border of the sternopleura ; two broad 

 contiguous hypopleural spots, which are margined inwardly, in front of the 

 insertion of the halteres, with a conspicuous blackish patch. The anterior supra- 

 alar bristle is well developed, like the two posterior ones ; the four scapular ones 

 are long and strong ; the pteropleural is well developed. Scutellum yellow, with 

 the base narrowly reddish brown, and with a pair of long apical bristles. Mesophragma 

 reddish, with the above-mentioned dark spot on the sides. Halteres whitish yellow. 

 Abdomen elongate, rather constricted near the base ; hind border of the second 

 segment with a broad yellowish band, which is more or less interrupted in the 

 middle ; sides of the first, sometimes of the second and middle of the third 

 segments provided with more or less distinct, but not sharply defined, dark brown 



♦Bull. Ent. Research, vi., Sept. 1915, pp. 85-101, 14 figs. 



