177 



NEW ETHIOPIAN FRUIT-FLIES OF THE GENERA TRIDACUS 



AND DACUS (DIPT.). 



By Prof. M. Bezzi, 

 Turin, Italy. 



Some additional fruit-flies of the genus Dacus (s.l.) from the Ethiopian Region 

 have been recently submitted to me for study by the Imperial Bureau of Entomology, 

 through the kindness of Dr. G. A. K. Marshall, the Director.* 



The riches of the Ethiopian Fauna in forms of this genus seem to be inexhaustible, 

 for even a small collection of these flies always brings to light new and often very 

 strikingly characterised species. It is interesting to note that the tendency of the 

 wings to be adorned with bands is more frequent in Africa than was previously 

 believed, as is shown by the discovery of D. hamatus, Bezzi, and of the new 

 D. trigonus, here described. In both these cases, however, the imagines at present 

 known have the wing pattern of another type and much less evolved than that of 

 the Oriental species of Bactrocera. 



Genus Tridacus, Bezzi, 1915. 

 1. Tridacus stylifer, sp. nov. (fig. 1). 



Easily distinguished from all the other known species of the present genus on 

 account of its very simple wing pattern, even the brown anal stripe being quite 



Fig. 1. Tridacus stylifer, Bezzi, sp. n. 



wanting. Falling into section 16 of my Key (I.e., 89) with kumercdis, which is 

 however at once distinguished by the presence of a broad, fuscous anal stripe 

 on the wings. In Dacus scaber, Loew, from CafEaria (possibly a Tridacus) the 

 anal stripe seems to be wanting ; but it is described as having a very short ovipositor, 

 and an infuscated small cross-vein. 



0. Length of body , 6-7 mm. ; length of wing, 6-7 mm. Head of a yellowish colour ; 

 occiput rather shining, reddish in the middle and above, narrowly yellow at the eye 

 border above and more broadly yellow below ; ocellar dot black, small ; frons about 

 twice as long as broad, of a rather dark yellowish colour, opaque, but shining on the 

 narrow orbits and on the brownish vertical plates ; it shows in the middle a rounded, 

 reddish-brown spot, and is more pale in front, above the shining brown lunula ; there 

 are only 2 pairs of lower fronto-orbital bristles. Face entirely shining yellow, quite 



* For the previous papers see : Bull. Ent. Eesearch, vi, Sept. 1915, pp. 85-101, 14 figs., 

 and viii, Aug. 1917, pp. 63-71, 6 figs. 



(C507) Wt.P3/130. 1,000. 3.19. B.&F.,Ltd. G.ll/1. A 



