Taxonomic revision of the mydas-fly genera Eremohaplomydas Bequaert, 1959, Haplomydas Bezzi, 1924, and Lachnocorynus Hesse, 1969 (Insecta, Diptera, Mydidae) Author Boschert, Claire Rice University, Houston, TX, USA Author Dikow, Torsten https://orcid.org/0000-0003-4816-2909 Department of Entomology, National Museum of Natural History, Smithsonian Institution, 10 th Street and Constitution Avenue NW, Washington, DC 20560, USA dikowt@si.edu text African Invertebrates 2022 2022-03-25 63 1 19 75 http://dx.doi.org/10.3897/afrinvertebr.63.76309 journal article http://dx.doi.org/10.3897/afrinvertebr.63.76309 2305-2562-1-19 F849C700225A4923AE1962882F933E83 B0655A9F7BBC582691EC0F00E156BA38 Eremohaplomydas stomachoris sp. nov. Figs 16-18 , 33 , 57 Diagnosis. The species is distinguished from congeners by the macrosetose dorso-median occipital setae, the small and slender size (wing length 6.3 mm), and the restricted distribution in the northern Namib Desert. Figures 16-18. Eremohaplomydas stomachoris sp. nov. (♀ holotype, AAM-003035, Zenodo https://doi.org/10.5281/zenodo.6083930): 16 dorsal (https://doi.org/10.5281/zenodo.6083983) 17 lateral (https://doi.org/10.5281/zenodo.6083985) 18 head anterior (https://doi.org/10.5281/zenodo.6083987). Scale bars: 5 mm. Etymology. Greek stoma = mouth, choris = without. The specific epithet refers to the extremely short and minute proboscis in this species. Description. Female. Head : black, facial gibbosity brown, in general golden pubescent, ventrally and posteriorly white pubescent, white setose, regular, cylindrical setae; width distinctly greater than thorax (at postpronotal lobe), interocular distance on vertex larger than at ventral eye margin; vertex between compound eyes +/- horizontally straight, medially only slightly below dorsal eye margin, vertex golden pubescent, light brown; ocellar triangle apubescent; facial gibbosity distinct, well-developed and discernible in lateral view, mystax covering entire facial gibbosity, sparse, white; parafacial area approximately as wide as 1/2 width of central facial gibbosity (at same level); frons not elevated, golden pubescent, yellow; occiput predominantly grey pubescent, dorsally golden pubescent, yellowish to light brown setose, median occipital sclerite yellowish macrosetose; pocl macrosetae absent; postgena sparsely white pubescent, long, sparsely white setose; clypeus comprised of single sclerite, entirely sclerotized medially, flat to protruding (convex) ventrally, ventrally simple, posterior to proboscis, laterally connected to face by sclerotized cuticle; proboscis very short, vestigial, knob-like, light brown; labellum small, as wide as prementum, length indiscernible, sclerotization indiscernible; maxillary palpus laterally compressed (triangular), light brown, slightly longer than proboscis. Antenna : brown; scape brown setose dorsally, asetose ventrally; pedicel light brown setose dorsally and ventrally; postpedicel cylindrical in proximal 1/4 , symmetrically bulbous in distal 3/4 , ≥ 4.0 times as long as combined length of scape and pedicel, asetose; apical seta-like sensory element situated apically in cavity on postpedicel. Thorax : light brown, predominantly grey pubescent; scutum black, brown posteriorly, surface entirely smooth, predominantly grey pubescent, broad median and sublateral stripes reaching transverse suture brown pubescent, postsuturally with 2 large sublateral sparsely grey pubescent spots, scutal setation comprised of distinct rows of long dorsocentral setae and lateral scutal setae; dc setae pre- and postsuturally white or yellow, acr setae absent, lateral scutal setae yellow, npl setae 0, spal setae 0, pal setae 0; proepisternum apubescent, long white setose; proepimeron grey pubescent, asetose; antepronotum antero-medially smooth (without any indentation); lateral postpronotum long white setose; postpronotal lobe yellow, white pubescent, long white setose; scutellum grey pubescent, discal scutellar setae absent, apical scutellar setae absent; mesopostnotum grey pubescent, asetose; anatergite grey pubescent, asetose; katatergite grey pubescent, long white setose, slightly elevated, smoothly convex; anepisternum grey pubescent, anteriorly white setose, posteriorly long white setose, scattered white setose antero-ventrally; katepisternum dorsally grey pubescent, ventrally apubescent, single white seta posteriorly; anepimeron grey pubescent, long white setose; katepimeron grey pubescent, asetose; meron grey pubescent dorsally, apubescent ventrally, asetose; metakatepisternum large; metanepisternum grey pubescent, asetose; metepimeron yellow (contrasting color of T1), grey pubescent, long white setose, +/- flat, infra-halter sclerite absent. Legs : light brown to brown, setation comprised of white to yellowish setae, femur with laterally compressed setae; pro coxa sparsely white pubescent, short white macrosetose; mes coxa sparsely white pubescent, short white macrosetose anteriorly, long white laterally compressed setae posteriorly; met coxa laterally unsclerotized (membrane between coxa and metakatepisternum clearly visible), sparsely white pubescent, short white macrosetose anteriorly, long white laterally compressed setae posteriorly; met trochanter sparsely setose medially; pro + mes femur light brown to brown, met femur light brown to brown, evenly clubbed in distal 3/4 , macrosetose, 1 antero-ventral and 1 postero-ventral row of macrosetae, postero-ventrally long white, appressed setose; pro tibia laterally arched; mes tibia laterally arched; met tibia straight, met tibia cylindrical with distinct ventral keel without terminal spur, 2 long macrosetae originating near tip of keel, postero-laterally regular setose only; pro + mes tarsomere 1 approximately as long as individual tarsomeres 2, 3, or 4, met tarsomere 1 as long as individual tarsomeres 2, 3, or 4; pulvillus well-developed, as long as well-developed claw, and as wide as base of claw; setiform empodium absent. Wing : length = 6.3 mm; hyaline throughout, veins light brown, microtrichia absent; cells r1, r4, m3, + cua closed, r5 open; C terminating at junction with R1; Sc long, terminating in C proximal to r-m; R4 terminates in R1; R5 terminates in R1 and R4 simultaneously; auxiliary vein (R3) at base of R4 absent; R4 and R5 widest apart medially; r-m distinct, R4+5 and M1 apart, connected by crossvein; M1 straight at r-m (not curving anteriorly), M1 (or M1+M2) terminates in C (not reaching wing margin); base of M3+M4 present, M3+M4 not terminating together in C (not reaching wing margin), M4 and CuA split proximally to m-cu (cell m3 narrow proximally); CuP straight, cell cup wide, CuP and wing margin further apart proximally than distally; alula well-developed; halter light yellow, apubescent, asetose. Abdomen : light brown to brown, setation comprised of scattered white setae, T2-4 parallel-sided and not constricted waist-like, T surface entirely smooth; T1 brown with yellowish posterior margin, T2-7 brown medially and laterally with yellowish posterior margins, sub-laterally yellowish, slightly angled longitudinal striping; T1 grey pubescent, T2-3 sparsely grey pubescent narrowly anteriorly and medially, T4-7 apubescent; T1-7 short white setose; S1-7 light brown; S apubescent; S1-7 sparsely short white setose; bullae on T2 oval, small, yellow, surface entirely smooth, T2 surface anterior to bullae smooth. ♀ abdomen and genitalia : densely arranged anteriorly directed setae present on T7-8 and S7-8; T8 anterior apodeme indiscernible (not dissected), auxiliary spiracle indiscernible (not dissected); T9 formed by wide, rectangular sclerite with median protuberance; T9+10 entirely fused (sclerites indistinguishable), T10 divided into 2 heavily sclerotized acanthophorite plates; 5-7 acanthophorite spines per plate. Male. unknown. Type locality. Namibia: Kunene: Kaokoveld, Orupembe, 21 km S ( 18°19'24"S , 012°29'12"E , -18.32333 , 12.48667 ). Material examined. Namibia : Kunene : 1♀ Kaokoveld , Orupembe , 21 km S , 18°19'24"S , 012°29'12"E , 1970-05-01 , Brown, H. ( AAM-003035 , Holotype , SANC ) . Distribution, biodiversity hotspots, phenology, and biology. Known only from a single locality in the Namib Desert in northern Namibia (Fig. 57 ). A rarely collected species known only from a single female specimen collected in 1970 (Table 1 ). The species is not known to occur in any currently recognized biodiversity hotspot. Adult flies are active in May in mid-autumn (Table 2 ), which is a time at the end of a moister period and decreasing temperatures in this part of the Namib Desert (data for Anabib, Namibia, see https://www.worldweatheronline.com/anabib-weather/kunene/na.aspx). Nothing is known of the biology. Remarks. The type locality of Eremohaplomydas stomachoris sp. nov. lies geographically very close to that of Eremohaplomydas desertorum . However, the single female specimen of E. stomachoris sp. nov. is morphologically more similar to Eremohaplomydas gobabebensis sp. nov. from the central Namib Desert (more than 600 km further south) than it is to E. desertorum (see also Discussion). Furthermore, E. stomachoris sp. nov. has been collected in early May, at least a month earlier in autumn than E. desertorum (Table 2 ).