Eremohaplomydas gobabebensis, Boschert & Dikow, 2022

Boschert, Claire & Dikow, Torsten, 2022, Taxonomic revision of the mydas-fly genera Eremohaplomydas Bequaert, 1959, Haplomydas Bezzi, 1924, and Lachnocorynus Hesse, 1969 (Insecta, Diptera, Mydidae), African Invertebrates 63 (1), pp. 19-75 : 19

publication ID	https://dx.doi.org/10.3897/afrinvertebr.63.76309
publication LSID	lsid:zoobank.org:pub:F849C700-225A-4923-AE19-62882F933E83
DOI	https://doi.org/10.5281/zenodo.7577340
persistent identifier	https://treatment.plazi.org/id/745D49C1-62B8-4884-9F7F-2B82523373D3
taxon LSID	lsid:zoobank.org:act:745D49C1-62B8-4884-9F7F-2B82523373D3
treatment provided by	African Invertebrates by Pensoft
scientific name	Eremohaplomydas gobabebensis
status	sp. nov.

Treatment

Eremohaplomydas gobabebensis sp. nov.

Figs 10-12 View Figures 10–12 , 13-15 View Figures 13–15 , 32 View Figures 31–34 , 53 View Figures 53–55 , 56 View Figure 56

Diagnosis.

The species is distinguished from congeners by the densely arranged dorso-ventrally flattened setae on legs, the absence of the base of vein M3+M4, the overall golden pubescence, and the restricted distribution in the central Namib Desert.

Etymology.

This species is named after the Gobabeb Namib Research Institute (www.gobabeb.org) where it was collected for the first time in November 2018. The specific epithet is to be treated as a noun in apposition.

Description.

Female. unknown.

Male. Head: black, facial gibbosity brown, in general golden pubescent, ventrally and posteriorly white pubescent, white setose, laterally compressed 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, white setose; ocellar triangle apubescent; facial gibbosity distinct, well-developed and discernible in lateral view, mystax covering entire facial gibbosity, white; parafacial area approximately as wide as ½ width of central facial gibbosity (at same level); frons not elevated, golden pubescent, white setose; occiput predominantly white pubescent, dorsally golden pubescent, white setose, median occipital sclerite white setose, laterally compressed setae; pocl macrosetae absent; postgena apubescent, long, sparsely white setose; clypeus comprised of inverted U-shaped sclerite, dorsal ½ sclerotized medially to form plate, recessed (concave), ventrally simple, posterior to proboscis, laterally connected to face by sclerotized cuticle; proboscis very short, vestigial, knob-like, yellow; labellum small, as wide as prementum, length indiscernible, sclerotization indiscernible; maxillary palpus laterally compressed (triangular), light brown, slightly longer than proboscis.

Antenna: light brown to brown; scape white setose dorsally, asetose ventrally; pedicel white setose dorsally and ventrally; postpedicel cylindrical in proximal 1/5, symmetrically bulbous in distal 4/5, ≥ 5.0 times as long as combined length of scape and pedicel, asetose; apical seta-like sensory element situated apically in cavity on postpedicel.

Thorax: brown, scutum golden pubescent, pleura white pubescent; scutum uniformly black, surface entirely smooth, golden pubescent, scutal setation comprised of long white setae with distinct rows of long dorsocentral setae and dense lateral scutal setae; dc setae pre- and postsuturally white, acr setae absent, lateral scutal setae white, 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 light brown, golden to light brown pubescent, long white setose; scutellum golden pubescent, discal scutellar setae absent, apical scutellar setae absent; mesopostnotum golden pubescent, asetose; anatergite golden pubescent, asetose; katatergite white pubescent, long white setose, slightly elevated, smoothly convex; anepisternum white pubescent, anteriorly white setose, posteriorly densely long white setose, scattered long white setose centrally; katepisternum dorsally white pubescent, ventrally apubescent, asetose; anepimeron white pubescent, long white setose; katepimeron white pubescent, asetose; meron white pubescent dorsally, sparsely white pubescent ventrally, asetose; metakatepisternum large; metanepisternum white pubescent, asetose; metepimeron yellow (same color as T1), white pubescent, long white setose, ± flat, infra-halter sclerite absent.

Legs: light brown to brown, setation comprised of white laterally compressed setae predominantly covering surface; pro coxa apubescent, sparse white laterally compressed setae; mes coxa apubescent, asetose anteriorly, short white laterally compressed setae posteriorly; met coxa laterally unsclerotized (membrane between coxa and metakatepisternum clearly visible), apubescent, asetose anteriorly, short white laterally compressed setae posteriorly; met trochanter setose medially; pro + mes femur light brown to brown, met femur light brown to brown, distinctly clubbed for nearly entire length, 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 laterally arched, met tibia cylindrical with ventral keel terminating into distinct spur, spur not projecting beyond tip of tibia, postero-laterally long white, appressed setose; 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 = 4.2-5.7 mm; hyaline throughout, veins light yellow, 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 curves slightly anteriorly at r-m, M1 (or M1+M2) terminates in C (not reaching wing margin); base of M3+M4 absent, 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 dense long white setae, T2-4 parallel-sided and not constricted waist-like, T surface entirely smooth; T1-4 light brown, T5-7 brown; T entirely golden pubescent; T1-7 long white setose; S1-5 brown with white posterior margin, S6-7 dark brown; S apubescent; S1 asetose, S2-7 long white setose; bullae on T2 oval, brown, surface entirely smooth, T2 surface anterior to bullae smooth.

♂ abdomen and terminalia: T1-8 well-developed; T7-8 anteriorly with 2 lateral apodemes; S6 regular, without any special setation postero-medially; S8 simple plate, entire (undivided) ventro-medially, not fused to T8 dorso-laterally; epandrium formed by single sclerite (fused medially ± entirely), distally in dorsal view pointed postero-laterally; subepandrial sclerite without lateral or median protuberances; hypandrium ± flat, divided ventro-medially by unsclerotized area into 2 sclerotized halves, entirely fused with gonocoxite, forming a gonocoxite-hypandrial complex, supra-hypandrial sclerite absent; gonocoxite simple, short, hook-like, without median or lateral protuberance, gonocoxal apodeme absent; 2 functional phallic prongs, short with broad lateral flange, medio-distally connected, parallel or diverging laterally, distally straight or only diverging slightly laterally; phallic epimere absent; lateral ejaculatory process absent; ejaculatory apodeme formed by single dorso-ventrally oriented plate; ventro-median margin of parameral sheath heavily sclerotized (appearing entirely closed); parameral sheath long, sperm sac entirely covered; sperm sac appearing ± heavily sclerotized.

Type locality.

Namibia: Erongo: Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed (23°24'56"S, 014°54'43"E, -23.41556, 14.91194).

Material examined.

Namibia: Erongo: 1♂ Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed , 23°24'56"S, 014°54'43"E, 317 m, 2018-11-24 collected a.m. (9:00-noon), dry, sandy, partly wooded riverbed, resting on sand, Dikow, T. ( USNMENT01518262 , Holotype, NMNW) GoogleMaps ; 1♂ Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed , 23°24'56"S, 014°54'43"E, 317 m, 2018-11-24 collected a.m. (9:00-noon), dry, sandy, partly wooded riverbed, resting on sand, Dikow, T. ( USNMENT01518263 , Paratype, NMNW) GoogleMaps ; 1♂ Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed , 23°24'56"S, 014°54'43"E, 317 m, 2018-11-24 collected a.m. (9:00-noon), dry, sandy, partly wooded riverbed, resting on sand, Dikow, T. ( USNMENT01518261 , Paratype, USNM) GoogleMaps ; 1♂ Namib-Naukluft National Park, Gobabeb 20 km NW on D1983, Kuiseb riverbed , 23°24'56"S, 014°54'43"E, 317 m, 2018-11-24 collected a.m. (9:00-noon), dry, sandy, partly wooded riverbed, resting on sand, Dikow, T. ( USNMENT01518260 , Paratype, USNM) GoogleMaps ; 1♂ Namib-Naukluft National Park, Gobabeb , dunes W of Kuiseb riverbed, 23°33'48"S, 015°01'58"E, 401 m, 2018-11-21 collected a.m. (9:00-noon), small vegetated dunes, resting on sand, Dikow, T. ( USNMENT01518012 , Paratype, USNM) View Materials GoogleMaps ; 1♂ Namib-Naukluft National Park, Gobabeb , small dunes W of Kuiseb River, 23°33'50"S, 015°01'59"E, 398 m, 2018-11-23 collected p.m. (noon-15:00), partly vegetated dune, resting on sand, Dikow, T. ( USNMENT01518339 , Paratype, USNM) GoogleMaps .

Distribution, biodiversity hotspots, phenology, and biology.

Known only from two localities in the central Namib Desert in Namibia (Fig. 56 View Figure 56 ). A rarely collected species known only from seven specimens from three collecting events in 2018 (Table 1 View Table 1 ). The species is not known to occur in any currently recognized biodiversity hotspot. Adult flies are active in November in late spring (Table 2 View Table 2 ), which is a time at the beginning of a moister period and rising temperatures in this part of the Namib Desert (data for Gobabeb, Namibia, see https://www.worldweatheronline.com/gobabeb-weather/erongo/na.aspx). So far, only males have been collected and they were observed to fly very low above the ground and appeared to inspect the base of single grass plants and dart at high speed across the sand to the next plant. At the Gobabeb locality, the flies were collected flying among Centropodia glauca ( Poaceae , Gha Grass, https://www.gbif.org/species/5680035) and at the 20 km N Gobabeb locality the flies darted among Cladoraphis spinosa ( Poaceae , Spiny Love Grass, https://www.gbif.org/species/4152290, see habitat photographs with the grasses in the foreground in Figs 1 View Figures 1–2 , 2 View Figures 1–2 ). Both grass species are native and widely distributed in the western parts of southern Africa including the Namib Desert ( van Oudtshoorn 2012). The male flies possibly inspected the grasses in search for females resting in the shade although the junior author was not able to observe or collect any females. In general, the flies were very difficult to observe and collect due to their high flight speed, light colouration, and small size.