Lispe patersoni, Vikhrev, 2021

Vikhrev, Nikita E., 2021, Lispe (Diptera, Muscidae) of Africa, Amurian Zoological Journal XIII (3), pp. 369-400 : 391-392

Identification key for Lispe of Africa, ♂ and ♀

Emden’s (1941) key for African Lispe divided the fauna into two large groups: those with dark versus yellow palpi. I do not agree with using such a secondary character which may be intraspecifically variable for the main division. Couri et al. (2006) used as the main diagnostic character for Madagascan Lispe the amount of dorsocentral setae, this approach seems more reasonable, but it also has its drawbacks. First, it is difficult to apply to species with weak dorsocentrals, especially to aged specimens with worn mesonotum. Second, this character may vary intraspecifically, for example, in L. tentaculata male has 2+3 dc whereas the female 2+4 dc. I believe that the tibial chaetotaxy is a more reliable and the easiest to apply characteristic, however, also not in all cases.

In my opinion, a good key should use the most reliable and easy-to-find characters (1) and be organized so that closely related species run together, not in different parts of the key (2). I tried to make the key this way, but sometimes it was impossible to meet both conditions, thus L. loewi belonging to the L. palposa group runs among species of the L. caesia group.

I tried to mention as many additional characters in the key as possible. Hopefully this will allow a user to be more confident in the identifications. On the other hand, the key has become larger. I can offer a know-how: since more than half of African specimens of Lispe belong to the most common species, start with checking couplets 46–48. If it is not L. pectinipes then you have something more interesting.

1. Hind coxa with setae on inner posterior margin. (From brackish to hypersaline water, either seashores or inland salt basins. t1 usually with p; t2 with 1 p and 0–1 ad; t3 always without pd. ♂: frons often densely silver-white dusted. ♀: f1 usually with short v huntingspines.)................ 2

— Hind coxa bare on inner posterior margin ...................................... 13

2. t1 without p. (2+3 dc, all strong. Abdominal tergites 3–4 with a large black triangular medianspoteach.)..................... 3

— t1 with p .............................. 4

3. Frons black, frontal triangle narrow. t2 without ad. Palpi black. Wing darkened at apex. Small (4.5 mm), dark species known from E African seashores ( Fig. 35 ). ♂: t3: with ad below middle and preapical d fine and long (about 0.4x as long as length of tibia); a to av surfaces with 7–8 setae in apical half. tar3-1 with av and pv rows of waved setulae ( Figs 30–34 ).................................. patersoni sp. nov.

— Frons densely whitish (♂, Fig. 16) or yellow (♀) dusted, frontal triangle widened, with convex margins. t2 with ad. Palpi partly yellow. Wing hyaline. Large (7 mm) species known from seashore of S-W Madagascar. ♂: tar3-1 thickened, with ventral tuft of long setae..................................... argentata Couri, Pont and Penny

4. Meron with hairs above hind coxa. t3 without av, with 1 ad only. Abdomen with a conspicuous dark midline. 2+3 dc. N Africa and Sudan. ♂: Vibrissae absent. Mid leg modified: t2 with 1 ad seta placed distinctly above middle, 1(2) p seta(e) short and weak, also placed above middle; v surface at apical half with 1–2 strong spine-like seta(e) and a row of longer fine setae ( Vikhrev 2015: fig. 17). tar2-1 with long fine curled ventral setae at base. ♀: t2 with 2 medium strong ad and 3 short pd, either ad and pd widely separated, upper ad and pd set above middle of tibia ( Vikhrev 2020: fig. 46)................... loewi Ringdahl

— Meron bare. t3 with 1 or more av. t2 with 1 p and 0– 1 ad. Abdomen without black midline............................... 5

5. dc setae may be described as 0+2 or 2+4 dc (medium/weak, medium/weak + weak, weak, strong, strong) depend on species or specimen. t2 without ad. Frontal triangle broad, with convex margins; frons in ♂ densely silvery dusted, in ♀ white or yellow dusted. Vibrissae in ♂ weak............ 6

— 2+3 dc (all strong)..................... 8

6. Palpi dark. Body length over 6.5 mm. All femora with strong ventral spines in both sexes. (Abdomen with a pair of dark spots on tergites 3 and 4, in ♂ also tergite 5 antero-laterally darkened. 2+4 dc. ♂: hind tarsus with dense brush of hairs on posterior side.) ( Zhang et al. 2016, figs 1d, 12, 13; Vikhrev 2020, figs 10–15)................................... candicans Kowarz

— Palpi yellow. Body length less than 6.5 mm. Only ♀ with weak ventral spines on fore and mid femora....................... 7

7. In both sexes frons evenly silvery, borders between fronto-orbital plates, frontal vitta and frontal triangle hardly distinct. Abdomen evenly whitish-grey, unmarked. dc setae may be described as 0+2 or 2+4 dc. ♂: t3 with 1 av. tar3-1 thickened ( Hennig 1960: textfig. 97; Zhang et al. 2016: fig. 1H)..................... leucocephala Loew

— In both sexes frontal triangle clearly distinct whitish in ♂, yellowish in ♀. Abdomen with distinct pairs of dark spots on tergite 4, tergite 3 with or without spots. 2+4 dc, but there are specimens with 2+3 dc. ♂ ( Figs 9–12 ): t3 with 1 av and 1 ad. tar3-1 only slightly thickened in basal half; posteriorly with a dense row of p setulae...................... andrefana sp. nov.

Figures

Figs 30–35. L. patersoni sp. nov.: 30 — the holotype, general view; 31 — the holotype, head; 32 — the holotype, abdomen, posterior view; 33 — cercal plate; 34 — left hind tibia, male; 35 — the exact collecting site of the type series in Mtwara town, flies were found on the stony littoral zone (photo: https://donquiblog.com/tag/old-boma/)

Figs 7–12. L. alkalina sp. nov. (7–8): 7 — female, general view; 8 — female, head; L. andrefana sp. nov. (9–12): 9 — the holotype, general view; 10 — the holotype, head; 11 — the holotype, abdomen, posterior view; 12 — cercal plate