88 



PROF. M. BEZZI. 



(b) Wings with a more or less distinct complete costal border. 



23. histrigatus, Loew. 



24. ciliatus, Loew. 



25. sigmoides, Coq. 



26. brevis, Coq. 



27. brevistylus, Bezzi. 



28. africanus, Adams. 



Fig. 3. Wings of Dacus : — Veins : a, costa ; h, auxiliary vein ; c, first longitudinal ; 

 d, second longitudinal ; e, third longitudinal ; /, fourth longitudinal ; g, fifth longi- 

 tudinal ; h, sixth longitudinal ; i, axillary ; j, humeral cross-vein ; k, anterior cross- 

 vein ; ly posterior cross-vein ; m, basal cross-vein ; n, anal cross-vein. Cells : A, AV 

 costal cell ; B, subcostal cell ; B\ stigma ; C, marginal cell ; D, submarginal ; E^ 

 first basal ; F, first posterior ; G-, second basal ; H, discoidal ; I, second posterior ; 

 J, anal ; K, third posterior ; L, axillary cell. 



In a collection of Ethiopian Dacus which I have received for study from the 

 Imperial Bm'eau of Entomology, I have fomid a number of species ; and by adding- 

 to them those in my collection, I can give the following table for the species known 

 to me : — 



1 (20). Thorax with three supra- alar macrochaetae, the anterior one being well 

 developed ; species more robust and of larger size (8-12 mm., but usually 9-12 mm.), 

 with the wing pattern well developed and often very broad {Tridacus, subgen. n.). 



2 (13). Wings with the brown costal border extended to the middle of the first 

 posterior cell, or even to the fourth vein, or sometimes with a broad brown spot 

 surpassing the fourth vein. 



3 (6). Wings with a broad rounded brown spot, filling almost the whole of the 

 first posterior cell and extending to the upper part of the second posterior cell ; species- 

 of greater size (10-12 mm.), with no yellow humeral spot and with the yellow meta- 

 pleural stripe very narrow. 



4 (5). Yellow spot on the hypopleura well developed and rather broad ; 

 thorax with three yellow stripes behind the suture ; scutellum darkened above. 



1. lounsburyi, Coq. 



5 (4). No distinct hypopleural spot; thorax without yellow stripes; scutellum 

 entirely yellow. . . . ;■ 2. sphaeristicits, Speis^ 



