Key for species of Lactistomyia Melander 1 Hind tibia tubular, without longitudinal furrow; colored stigma; hind femur with clearer apex than the base, complete and regular anteroventral and posteroventral rows of spines, ventral surface wide and flat- tened.............................................................................................................................................................2 - Hind tibia flattened anteriorly, with soft longitudinal furrow; stigma and hind femur variable.................3 2 Hind tibia yellow; hypandrial lobe widened (Fig. 8) ........................................................... L. lepida sp. n - Hind tibia yellow with subapical brown ring; hypandrial lobe triangular with narrowed apex (Fig. 31) ..... ..................................................................................................................................... L. paranaensis sp. n. 3 Stigma colored (Figs. 55–57, 60–63)...........................................................................................................6 - Stigma hyaline (Figs. 54, 58, 59)................................................................................................................ 4 4 Scutum with dorsal square shiny area on basal third; hind femur with complete and regular anteroventral and posteroventral rows of spines, ventral surface wide and flattened ................................ L. minuta sp.n. - Scutum totally pruinose; hind femur with anteroventral and posteroventral rows of spines incomplete and irregular, ventral surface narrow and not flattened.....................................................................................5 5 Hind femur dark brown, clearer apically; wing darker just in the basal extremity (Fig. 54) ....... L. hyalina - Hind femur homogeneously brown; wing darker besides the basal half (Fig. 59) ...................... L. nigripes 6 Hind tibia with ventral sub-basal tubercle...................................................................................................7 - Hind tibia without ventral tubercle..............................................................................................................9 7 Wing homogeneously brown; femur brown with clearer apex; tubercle of hind tibia reduced (Figs. 6, 53); hypandrial lobe with rounded apex.............................................................................................................8 - Wing dark basally, hyaline apically (Fig. 57); femur wholly brown; sub-basal tubercle of hind tibia greatly developed (Fig. 19); hypandrium split apically with two subequal lobes (Fig. 16) ............... L.mammifera 8 Scutellar bristles long (Fig. 1); hypandrial lobe expanded distally, as long as the hypandrium (Fig. 2) ...... ...................................................................................................................................................... L. insolita - Scutellar bristles short (Fig. 48); hypandrial lobe narrow, as long as half of the length of the hypandrium, with outer lateral preapical rounded protuberance (Fig. 49) ........................................ L. tuberculata sp. n. 9 Pleura clearer than scutum; hypandrial lobe with three-pointed apex (Fig. 39); right surstylus with dorsal margin not folded (Fig. 41) ............................................................................................... L. pulchra sp. n. - Pleura concolorous with scutum; hypandrial lobe almost truncated distally; right surstylus with folded, slightly sclerotised dorsal margin .................................................................................................. L.serrata

Published as part of Ale-Rocha, Rosaly, 2008, Revision of the Neotropical genus Lactistomyia Melander (Diptera, Hybotidae, Hybotinae), pp. 1-25 in Zootaxa 1692 on page 4, DOI: 10.5281/zenodo.180639