Review of the Palaearctic Acomopterella Zaitzev (Diptera, Sciaroidea, Mycetophilidae) Author Kallweit, Uwe text ZooKeys 2013 269 11 32 http://dx.doi.org/10.3897/zookeys.269.4252 journal article http://dx.doi.org/10.3897/zookeys.269.4252 1313-2970-269-11 Genus Acomopterella Zaitzev, 1989 Acomopterella Zaitzev, 1989: 134 (description); Sevcik & Chandler: 2008: 63 (discussion). Type species. Acomopterella arnaudi Zaitzev, 1989: 134 (by original designation) = Tetragoneura fallax Sherman, 1925: 20. Diagnosis. (based on Zaitzev's original genus description, with additions). Body length 4.6-5.9 mm. Head. With 3 ocelli. Mid ocellus slightly in front of the lateral ocelli. Lateral ocelli scarcely to distinctly remote from eye margin. Eyes with short setulae. Face rather flat, bare or setose. Clypeus oval, slightly bulging, setose. Face and clypeus loosely connected. Palpi pentamerous. Antennae 16-segmented, 2-3 times length of the thorax. Length of mesial flagellomeres 3-5 times their own width. Thorax. Scutum with short, close lying acrostichal and long erect dorsocentral bristles. Scutellum with 2 very long medial bristles. Mediotergite, laterotergites and pleura bare. Wing. Transparent. Wing membrane with microtrichia only. C, the apical part of ta, R1, R5, M1, M2, M4 and CuA with macrotrichia. C extending to the tip of R5. R4 present; ta oblique, slightly shorter than stem of fork M1 + M2. Base of M4 on level of base of ta or slightly more proximal. Vein A well developed, its tip behind the level of base of ta or ending slightly before. Between A and the stem of fork M4 + CuA lies the weakly sclerotized vein CuP, traceable as fold line. Legs. Long. Fore coxae with numerous long bristles on its frontal side. Apical part of mid coxae with bristles on its lateral and frontal surface. Hind coxae with a row of very long bristles on the hind lateral surface. Mid tibiae with well developed tibial organ on its basal part. Tarsal claws with teeth. Empodia well developed. Abdomen. Segments 1-7 of normal size. Tergite 8 vestigial; Sternite 8 exceeding half length of sternite 7. Tergite 9 rectangular, with deep distal incision. Gonocoxites with apical processes. Comments. The described genus belongs to the tribe Gnoristini in the subfamily Sciophilinae . It is similar to Dziedzickia marginata ( Dziedzicki 1885 ), but differing by bare laterotergites and a much longer vein ta. It differs from the Holarctic genus Acomoptera Vockeroth, 1980, in the position of Sc (in Acomopterella it joins R1, in Acomoptera C), in the shape of the cell between Rs and R4 (distinctly longer in Acomoptera ) and in the strikingly longer ta. The genus is also similar to Austrosynapha Tonnoir, 1929, known from South America, New Zealand and Tasmania. Typical in both genera is the absence of setae on the laterotergites and the presence of a relatively long oblique vein ta. In Austrosynapha vein R4 is absent.