Namibimydas (Figs 13–20): Hesse (1972) described the genus with its type species Namibimydas gaerdesi Hesse, 1972 based on one male and one female specimens collected at Walvis Bay (Erongo Region, Namibia). In 1974, Hesse added a second species, Namibimydas prinsi Hesse, 1974, based on a small series of specimens (4♂ and 3♀) collected at Paternoster (Western Cape Province, South Africa) and added notes on the flight behaviour, oviposition behaviour, and natural enemies of this species that were observed by the collector. Both species were collected at or near the Atlantic Ocean. Nothomydas (Figs 35–42): Hesse (1969) described the genus with its type species Nothomydas gariepinus Hesse, 1969 based on a single male specimen collected at Vioolsdrif (Northern Cape Province, South Africa). In 1972, Hesse added a second species, Nothomydas namaquensis Hesse, 1972, based on a small series of specimens (5♂ and 1♀) collected at Port Nolloth (Northern Cape Province, South Africa). While Port Nolloth is directly on the Atlantic Ocean coast, Vioolsdrif is much further inland and situated on the Orange River at the border between Namibia and South Africa.

Our knowledge of the two remaining Halterorchini genera is even less complete: Halterorchis (Fig. 46): Bezzi (1924) described the genus with its type species Halterorchis inermis Bezzi, 1924 based on a single female specimen collected at O'Okiep (29°35′42″S 17°52′52″E, Northern Cape Province, South Africa, holotype in SAMC) in his review of the mydids of southern Africa. Hesse (1969) added a second species to this genus, Halterorchis karooensis Hesse, 1969, also based on a single female specimen collected at Vogelfontein (32°38′39″S 21°52′56″E, Western Cape Province, South Africa, holotype in SAMC). To date, no additional specimens have been found that can unambiguously be assigned to Halterorchis and, unfortunately, the male of the genus remains unknown.

Mimadelphus (Fig. 47): Hesse (1972) described the genus with its type species Mimadelphus vellosus Hesse, 1972 based on a single male specimen collected in Namibia (no further locality available, holotype in SMNS). Here again, no additional specimens have so far been located and assigned to this genus and it is unfortunate that no further data are available that would help to elucidate when and where the type specimen was collected.

Bowden (1980) listed all above species in the Catalogue of Afrotropical Diptera.

Hesse (1972) described the tribal taxon Halterorchini placing in it the four genera Halterorchis, Mimadelphus, Namibimydas, and Nothomydas and provided an identification key to the genera. Hesse based Halterorchini on the reduced number of abdominal segments visible in pinned specimens in which tergite 8 and sternite 8 are hidden beneath segment 7. He further separated the genera in his key based on the length of the proboscis which is rudimentary in Halterorchis and Mimadelphus, but well-developed and long in Namibimydas (except N. psamminos sp. n.) and Nothomydas.

As can be seen from the above information, the four genera and seven species were represented by 19 specimens in total prior to this study. This review is based on an additional 34 specimens representing some of the previously known species, but also adding four previously unknown species for Namibimydas and Nothomydas. Halterorchis and Mimadelphus are excluded from the present study because more specimens, particularly ♂ of the former and ♀ of the latter, need to be available before the genera can be sufficiently diagnosed and compared to Namibimydas and Nothomydas. However, photographs of representatives of Halterorchis and Mimadelphus (Figs 46– 47) are provided for reference.

It should be noted that the delimitation, phylogenetic relationships, and the monophyly of Halterorchini has not been tested to date. However, the author is currently preparing a morphological phylogeny of Mydidae world-wide and representatives of both Namibimydas and Nothomydas are included in this analysis (Dikow in prep.).

Namibimydas Hesse, 1972: 158. Type species: Namibimydas gaerdesi Hesse, 1972 by orig. des.

ZooBank LSID: see Table 1.

Diagnosis: The genus is distinguished from other Syllegomydinae by its large size with a wing length of 11.2–17.7 mm, the generally grey colour caused by pubescence and dense white setation, the cylindrical metathoracic femora (not expanded), and structures of the male terminalia.

Description:

Male.

Abdomen and terminalia (Figs 1–12): T1–7 well-developed, entirely sclerotised, T8 posteromedially weakly sclerotised, with anterior transverse sclerotised bridge connecting lateral sclerites; T7–8 anteriorly with 2 lateral apodemes; S6 regular, without any special setation posteromedially, S8 not plate-like, medially narrow (broad laterally) and protruding ventrally (perpendicular to antero-posterior axis), not fused to T8 dorsolaterally; epandrium formed by two sclerites, separated medially and only joining anteriorly, distally in dorsal view blunt, evenly rounded; subepandrial sclerite without lateral or median protuberances; hypandrium strongly concave, laterally compressed, entirely sclerotised ventrally (forming a single sclerite), entirely fused with gonocoxite, forming a gonocoxite-hypandrial complex, supra-hypandrial sclerite absent in N. gaerdesi (Fig. 1) and present in N. prinsi, N. psamminos sp. n., and N. stuckenbergi sp.n. (Figs 4, 7, 10); gonocoxite dorsoventrally flattened (same height throughout, expanded laterally and medially), without median or lateral protuberance, gonocoxal apodeme absent; 2 functional aedeagal prongs, extremely long and thin, mediodistally free, parallel or diverging laterally, distally straight or only diverging slightly laterally; aedeagal epimere absent; lateral ejaculatory process absent; ejaculatory apodeme formed by single dorsoventrally oriented plate; ventro-median margin of dorsal aedeagal sheath heavily sclerotised (appearing entirely closed); dorsal aedeagal sheath long, sperm sac entirely covered; sperm sac appearing more-or-less heavily sclerotised.

Female.

Abdomen and genitalia (Fig. 21): Densely arranged anteriorly directed setae present on T6–8 and S6–8; T8 with broad anterior rectangular apodeme; T9 formed by wide, rectangular sclerite with median protuberance; T9+10 entirely fused, T10 divided into 2 heavily sclerotised acanthophorite plates, 5–9 acanthophorite spines per plate; 2 spermathecae, all equally large, formed by more-or-less expanded weakly sclerotised ducts; individual spermathecal duct long; S9 (furca) formed by 1 sclerite, ring-like (joined anteriorly and posteriorly), anterior furcal apodeme present, 2 lateral projections forming divided apodeme, lateral furcal apodeme absent, median furcal bridge absent.

Namibimydas gaerdesi: Hesse 1972: 161.

ZooBank LSID: see Table 1.

Diagnosis: The species is distinguished from congeners by the long proboscis that extends beyond the distal tip of the postpedicel (Fig. 13), the long abdominal setation in both males and females, the yellowish mystax (Figs 13, 14), and its apparent distribution in coastal (or near coastal) habitats from Swakopmund to Sandwich Bay in Namibia (Fig. 43).

Redescription:

Male.

Head: Black, in general densely grey pubescent; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes more-or-less horizontally straight, medially only slightly below dorsal eye margin, parafacial area less than half the width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white to yellowish, covering entire facial gibbosity; frons entirely grey pubescent, vertex entirely grey pubescent, postgena apubescent; setation: vertex white, frons white, ocp setae white, pocl macrosetae light brown; ocellar triangle apubescent; proboscis brown, long, projecting well-beyond fronto-clypeal suture and beyond tip of postpedicel; labellum small, as wide as prementum, about quarter length of prementum, unsclerotised laterally; maxillary palpus cylindrical, light brown, as long as pedicel.

Antenna: Brown, scape and pedicel white setose dorsally and ventrally; postpedicel cylindrical in proximal 0.4, symmetrically bulbous in distal 0.6, ≥5.0× as long as scape and pedicel combined; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax: Brown, predominantly grey pubescent; scutum medially dark brown, laterally brown, surface entirely smooth, lightly grey pubescent, broad sublateral stripes (interrupted postsuturally) and narrow paramedial stripes (not reaching posterior margin) apubescent, scutal setation comprised of long white setae with distinct rows of long dc setae and dense lateral scutal setae; dc setae pre- and postsuturally white, acr setae present, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; postpronotal lobe light brown, grey pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long white setose; scutellum grey pubescent, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite grey pubescent, mesopostnotum asetose, anatergite asetose, katatergite long white setose; katatergite more-or-less flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron long white setose; metanepisternum grey pubescent, asetose, metepimeron more-or-less flat, same colour as T1, grey pubescent, long white setose.

Leg: Light brown and brown, setation white setose, brown macrosetose; pro, mes, and met coxa lightly grey pubescent, long white setose; met trochanter setose medially; femur brown, met femur more-or-less cylindrical, only slightly wider than pro and mes femur, in distal half macrosetose, 1 anteroventral and 1 posteroventral row of macrosetae, posteroventrally long white, erect setose and setae arranged in distinct row; pro, mes, and met tibia straight, met tibia cylindrical, ventral keel absent, lateroposteriorly long white, erect setose and setae arranged in distinct row; pro and mes tarsomere 1 longer than tarsomere 2, but less than combined length of tarsomeres 2–3, met tarsomere 1 as long as combined length of tarsomeres 2–3; pulvillus well-developed, as long as welldeveloped claw, and as wide as base of claw; empodium absent.

Wing: Length 13.8–15.2 mm; hyaline throughout, veins light yellow, microtrichia absent; cells r₁, r₄, r₅, m₃, and cup closed; C terminates at junction with R₁; R₄ terminates in R₁; R₅ terminates in R₁; stump vein (R₃) at base of R₄ present, short not reaching R₂; 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 R₁; CuA₁ and CuA₂ split proximally to m—cu (cell m₃ narrow proximally); M+CuA₁ do not terminate together in C; A₁ undulating, cell a₁ wide, A₁ and wing margin further apart proximally than distally; alula well-developed, very large and partly overlapping with scutellum medially; haltere light brown.

Abdomen: Brown; setation comprised of dense long white setae, surface entirely smooth; T1–7 brown; T1–7 long white setose; T1 apubescent, T2–7 grey pubescent; S1–7 brown; S1 asetose, S2–7 sparsely white setose; S predominantly apubescent; T2–4 parallel-sided and not constricted waist-like; bullae on T2 black, transversely elongate, surface entirely smooth, T2 surface anterior to bullae smooth.

Terminalia (Figs 1–3): Supra-hypandrial sclerite absent (see Remarks). Female.

Thorax: Scutum predominantly grey pubescent, broad sublateral stripes (interrupted postsuturally) and narrow paramedial stripes (not reaching posterior margin) apubescent. Wing: Length 15.0–17.7 mm. Abdomen: Scattered white setose; Tl and anterior half of T2 long white setose, remaining T short white setose; bullae on T2 black, small and circular. Genitalia: 6–7 acanthophorite spines per plate.

Material examined: NAMIBIA: Erongo: 1♂ 1♀ Swakopmund, 5 km E, 22°40′51″S 14°35′10″E, riverbed with Tamarix (Tamaricaceae), 4.ii.1978, O. Lomholdt (AAM-000865-AAM-000866, ZMUC); 1♂ 1♀ Swakop River mouth, 22°41′25″S 14°31′30″E, coastal and riverbed dunes, 8–9.ii.1974, L. Lyneborg (AAM-000859-AAM-000860, ZMUC); 1♂ 1♀ Swakopmund, S side Swakop River mouth, 22°41′33″S 14°31′37″E, 9 m, sandy river bed and vegetated dunes, resting on sand, 3.ii.2012, T Dikow (AAM-007366AAM-007367, USNM); I♂ Walvis Bay, 22°57′27″S 14°30′19″E, 24.U940 (holotype, SMNS); 1♀ Walvis Bay, 20.i.1939 (allotype, SMNS); 1♀ Sandwichhafen (= Sandwich Harbour), 23°22′04″S 14°30′04″E, 19.i.1939 (AAM-003841, SMNS).

Type locality and distribution: Walvis Bay (22°57′27″S 14°30′19″E), Namibia (Fig. 43, GBIF resource #14003). Not known to occur in any biodiversity hotspot.

Remarks: When Hesse (1972) studied the specimens from the SMNS on which he based the new species description, he apparently did not study the female from Sandwichhafen also deposited in the SMNS. This specimen was studied by myself in October 2010 during a visit to the SMNS. The absence of a supra-hypandrial sclerite in this species is quite surprising. It is possible that this sclerite has been fused with the dorso-lateral margin of the gonocoxite-hypandrial complex and therefore forming a “roof” closing this structure dorsally (Fig. 1).

The species was recently collected at the Swakop River mouth by myself and observed to fly around the vegetated hummocks as shown in the habitat photograph in Fig. 44. One specimen was collected resting on dead, grey vegetation low above the ground where it is well-camouflaged by its overall grey coloration (see Fig. 13).

Namibimydas prinsi: Hesse 1974: 26. ZooBank LSID: see Table 1.

Diagnosis: The species is distinguished from congeners by the lack of ventral macrosetae on the metathoracic femora, the short abdominal setation in females (Fig. 16), and its apparent distribution in coastal habitats in the far south-western Western Cape Province of South Africa (Fig. 43).

Redescription:

Male.

Head: Black, in general densely grey pubescent; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between com- pound eyes more-or-less horizontally straight, medially only slightly below dorsal eye margin, parafacial area more than half width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white, covering entire facial gibbosity; frons entirely grey pubescent, vertex entirely grey pubescent, postgena lightly grey pubescent; setation: vertex white, frons white, ocp setae white, pocl macrosetae light brown; ocellar triangle apubescent; proboscis brown, long, projecting well-beyond fronto-clypeal suture, reaching half length of postpedicel; labellum small, as wide as prementum, about quarter length of prementum, unsclerotised laterally; maxillary palpus cylindrical, light brown, as long as pedicel.

Antenna: Brown, scape and pedicel white setose dorsally and ventrally; postpedicel cylindrical in proximal 0.4, symmetrically bulbous in distal 0.6, ≥4.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax: Brown, predominantly grey pubescent; scutum uniformly brown, surface entirely smooth, lightly grey pubescent, scutal setation comprised of long white setae with distinct rows of long dorsocentral setae and dense lateral scutal setae; dc setae preand postsuturally white, acr setae present, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; postpronotal lobe brown, grey pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long white setose; scutellum grey pubescent, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite grey pubescent, mesopostnotum asetose, anatergite long white setose, katatergite long white setose; katatergite more-or-less flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron long white setose; metanepisternum grey pubescent, asetose, metepimeron more-orless flat, same colour as T1, grey pubescent, long white setose.

Leg: Light brown, setation predominantly white; pro, mes, and met coxa lightly grey pubescent, long white setose; met trochanter setose medially; femur light brown, met femur more-or-less cylindrical only slightly wider than pro and mes femur, in distal half without ventral macrosetae, posteroventrally long white, erect setose and setae arranged in distinct row; pro, mes, and met tibia straight, met tibia cylindrical, ventral keel absent, lateroposteriorly long white, erect setose and setae arranged in distinct row; pro and mes tarsomere 1 longer than tarsomere 2, but less than combined length of tarsomeres 2–3, met tarsomere 1 as long as combined length of tarsomeres 2–3; pulvillus well-developed, as long as well-developed claw, and as wide as base of claw; empodium absent.

Wing: Length 11.2–12.5 mm; hyaline throughout, veins light yellow, microtrichia absent; cells r₁, r₄, r₅, m₃, and cup closed; C terminates at junction with R₁; R₄ terminates in R₁; R₅ terminates in R₁; stump vein (R₃) at base of R₄ present, short not reaching R₂; 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 M+M₂) terminates in R₁; CuA₁ and CuA₂ split proximally to m—cu (cell m₃ narrow proximally); M+CuA₁ do not terminate together in C; A₁ undulating, cell a₁ wide, A₁ and wing margin further apart proximally than distally; alula well-developed, very large and partly overlapping with scutellum medially; haltere light brown.

Abdomen: Brown; setation comprised of dense long white setose, surface entirely smooth; T1–7 brown with narrow yellow posterior margin; T1–7 long white setose; T1 apubescent, T2–7 grey pubescent; S1–7 brown; S1 asetose, S2–7 sparsely white setose; S predominantly apubescent; T2–4 parallel-sided and not constricted waist-like; bullae on T2 black, transversely elongate, surface entirely smooth, T2 surface anterior to bullae smooth.

Terminalia (10–12): Supra-hypandrial sclerite present.

Female.

Head: Pocl macrosetae yellow; labellum about 0.2 length of prementum. Antenna: ≥5.0× as long as combined length of scape and pedicel. Leg: met femur posteroventrally sparse long white, erect setose and setae arranged in distinct row; met tibia lateroposteriorly sparse long white, erect setose and setae arranged in distinct row; met tarsomere 1 less than combined length of tarsomeres 2–3. Wing: Length 12.3–12.7 mm; M1 straight at r—m (not curving anteriorly). Abdomen: Setation dense, very short white setose; T1–7 brown; Tl and antero-lateral corners of T2–3 long white setose, remaining T short white setose; S1–7 predominantly asetose; bullae on T2 black, oval. Genitalia: 6–7 acanthophorite spines per plate.

Material examined: SOUTH AFRICA: Western Cape: 3♀ 4♂ Paternoster, 32°48′25″S 17°53′01″E, 13.ii. 1973, A. Prins (holotype and paratypes, SAMC).

Type locality and distribution: Paternoster (32°48′25″S 17°53′01 ″E), South Africa (Fig. 43, GBIF resource #14003). Biodiversity hotspot: endemic to Cape Floristic Region.

ZooBank LSID: see Table 1.

Etymology: From Greek psamminos (of sand), referring to the apparent distribution along the eastern edge of the Namib desert sand dunes.

Diagnosis: The species is distinguished from congeners by the short proboscis that does not extend beyond the fronto-clypeal suture, the short and sparse abdominal setation in both males and females (Figs 17, 18), and its apparent distribution at the eastern edge of the Namib Desert sand dunes in Namibia (Fig. 43).

Description:

Male.

Head: Black, in general grey pubescent; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes more-or-less horizontally straight, medially only slightly below dorsal eye margin, parafacial area about as wide as half the width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white, covering entire facial gibbosity; frons entirely grey pubescent, vertex entirely grey pubescent, postgena apubescent; setation: vertex white or yellow, frons white or yellow, ocp setae white, pocl macrosetae yellow; ocellar triangle apubescent; proboscis brown, short, about half length of oral cavity; labellum small, as wide as prementum, about half length of prementum, unsclerotised laterally; maxillary palpus cylindrical, light brown, as long as pedicel.

Antenna: Brown, scape and pedicel white setose dorsally and ventrally; postpedicel cylindrical in proximal 0.4, symmetrically bulbous in distal 0.6, ≥4.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax: Brown, predominantly grey pubescent; scutum uniformly brown, surface entirely smooth, lightly grey pubescent, broad sublateral stripes (interrupted postsuturally) and narrow paramedial stripes (not reaching posterior margin) darker grey 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 present, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; postpronotal lobe light brown, grey pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long white setose; scutellum grey pubescent, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite grey pubescent, mesopostnotum asetose, anatergite long white setose, katatergite long white setose; katatergite more-orless flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron long white setose; metanepisternum grey pubescent, asetose, metepimeron more-or-less flat, same colour as T1, grey pubescent, long white setose.

Leg: Light brown, setation predominantly white; pro, mes, and met coxa lightly grey pubescent, long white setose; met trochanter setose medially; femur light brown, met femur more-or-less cylindrical only slightly wider than pro and mes femur, in distal half macrosetose, 1 anteroventral and 1 posteroventral row of macrosetae, posteroventrally sparse long white, erect setose and setae arranged in distinct row; pro, mes, and met tibia straight, met tibia cylindrical, ventral keel absent, lateroposteriorly sparse long white, erect setose and setae arranged in distinct row; pro and mes tarsomere 1 longer than tarsomere 2, but less than combined length of tarsomeres 2–3, met tarsomere 1 as long as combined length of tarsomeres 2–3; pulvillus well-developed, as long as welldeveloped claw, and as wide as base of claw; empodium absent.

Wing: Length 14.6–15.9 mm; hyaline throughout, veins light yellow, microtrichia absent; cells r₁, r₄, r₅, m₃, and cup closed; C terminates at junction with R₁; R₄ terminates in R₁; R₅ terminates in R₁; stump vein (R₃) at base of R₄ present, short not reaching R₂; 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 R₁; CuA₁ and CuA₂ split proximally to m—cu (cell m₃ narrow proximally); M₃+CuA₁ do not terminate together in C; A₁ undulating, cell a₁ wide, A₁ and wing margin further apart proximally than distally; alula well-developed, very large and partly overlapping with scutellum medially; haltere light brown.

Abdomen: Brown and light brown; setation comprised of dense short white setose, surface entirely smooth; T1 brown, yellow posterior margin, T2–3 light brown, anteriorly brown and posteriorly with yellow margin, T4–7 light brown with yellow posterior margin; T1 and anterior half of T2 long white setose, remaining T short white setose; T1 apubescent, T2–7 grey pubescent; S1–7 light brown; S1 asetose, S2–7 sparsely white setose; S predominantly apubescent; T2–4 parallel-sided and not constricted waist-like; bullae on T2 black, oval, surface entirely smooth, T2 surface anterior to bullae smooth.

Terminalia (Figs 4–6): Supra-hypandrial sclerite present.

Female.

Head: Brown, vertex and frons white setose. Antenna: Postpedicel ≥5.0× as long as combined length of scape and pedicel. Wing: Length 15.5 –17.1 mm. Abdomen: T1 brown, T2–7 brown with yellow posterior margin. Genitalia: 5–6 acanthophorite spines per plate.

Holotype: ♂ NAMIBIA: Hardap: Namib-Skeleton Coast National Park, Sesriem, Elim Dune, 24°27′28″S 15°46′37″E, 826 m, vegetated dune, resting on dead vegetation + sand, 9.ii.2012, T. Dikow (AAM-007360, NMNW).

Paratypes: NAMIBIA: Erongo: 1♂ Homeb, 16 km ESE Gobabeb (23), 23°38′12″S 15°10′55″E, 23– 25.i.1972, BMNH Southern Africa Expedition (AAM-000867, BMNH). Hardap: 1♀ Sesriem 137, 24°29′00″S 15°48′00″E, 5–8.iv.1972 (AAM-003056, NMNW); 2♂ 2♀ Namib-Skeleton Coast National Park, Sesriem, Elim Dune, 24°27′28″S 15°46′37″E, 826 m, vegetated dune, resting on dead vegetation + sand, T. Dikow, 9.ii.2012 (AAM-007361-AAM-007364, NMNW, USNM); I♂ Namib-Skeleton Coast National Park, Sesriem, Elim Dune, 24°27′35″S 15°46′21″E, 839 m, vegetated dune, resting on dead vegetation + sand, 10.ii.2012, T. Dikow (AAM-007365, USNM).

Type locality and distribution: Namib-Skeleton Coast National Park, Elim Dune near Sesriem (24°27′28″S 15°46′37″E), Namibia (Fig. 43, GBIF resource #14003). Not known to occur in any biodiversity hotspot.

Remarks: This species has been labelled previously as a new species and as a holotype by J. Bowden (unpublished) who named it Mesomydas syncrasis based on the male from Homeb deposited in the BMNH (see image at Morphbank #704382, note: ♂ terminalia previously removed). Since neither the generic nor the specific name have ever been published, they have no standing in nomenclature. Bowden was apparently unaware that the specimen he studied was congeneric with Namibimydas, which might be because this species, in contrast to all other known Namibimydas species, has a short proboscis and Hesse (1972) in describing the genus highlighted the fact that the proboscis is long.

At the start of this project only two specimens of this new species were known, i.e., the Homeb specimen referred to above and the Sesriem ♀ paratype (see image at Morphbank, #704386). Through field work conducted by myself in February 2012, eight specimens (six listed above plus one male preserved in 95% ethanol and one male in Kahle's fluid) were collected on the partly vegetated sand dune named Elim Dune in the Namib-Skeleton Coast National Park (24°27′28″S 15°46′37″E, habitat in Fig. 45) near Sesriem. The flies were flying very fast during the period between 9:00 a.m. to 1:00 p.m. (I did not visit this same dune in the afternoon) and were difficult to catch. I estimate that I only caught every fourth specimen I saw often after a prolonged chase with the fly very seldom interrupting its flightpath. The males were more active and appeared to fly from one vegetated hummock to another one in search for females. When a female, which were observed to rest close to the base of the plants in the shade, were encountered by the males both of them flew high into the air and could not be followed anymore. The flight behaviour of the males was very similar to aculeate Hymenoptera who often have a sustained, meandering flight low above the surface. The species was not encountered on a similarly vegetated dune some 18.5 km further SW along the road to Sossusvlei (24°36′17″S 15°40′10″E, 780 m) that was visited shortly after a series of specimens had been collected at Elim Dune.

ZooBank LSID: see Table 1.

Etymology: The species is named after and dedicated to the memory of Diptera systematist and taxonomist Brian Roy Stuckenberg, who contributed in many great ways to Afrotropical dipterology (Kirk-Spriggs 2012).

Diagnosis: The species is distinguished from congeners by the long proboscis that extends beyond the fronto-clypeal suture, but does not reach the tip of the postpedicel (Fig. 20), the entirely white mystax (Figs 19, 20), the long abdominal setation in both males and females, and its apparent distribution in coastal (or near coastal) habitats around Lüderitz in Namibia (Fig. 43).

Description:

Male.

Head: Black, in general densely grey pubescent; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes more-or-less horizontally straight, medially only slightly below dorsal eye margin, parafacial area less than half the width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white, covering entire facial gibbosity; frons entirely grey pubescent, vertex entirely grey pubescent, postgena lightly grey pubescent; setation: vertex white, frons white, ocp setae white, pocl macrosetae yellow; ocellar triangle apubescent; proboscis brown, long, projecting well-beyond fronto-clypeal suture, reaching half of length of postpedicel; labellum small, as wide as prementum, about quarter length of prementum, unsclerotised laterally; maxillary palpus cylindrical, light brown, as long as pedicel.

Antenna: Brown, scape and pedicel white setose dorsally and ventrally; postpedicel cylindrical in proximal 0.4, symmetrically bulbous in distal 0.6, ≥5.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax: Brown, predominantly grey pubescent; scutum medially dark brown, laterally brown, surface entirely smooth, lightly grey pubescent, broad sublateral stripes (interrupted postsuturally) and narrow paramedial stripes (not reaching posterior margin) darker grey 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 present, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; postpronotal lobe brown, grey pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long white setose; scutellum grey pubescent, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite grey pubescent, mesopostnotum asetose, anatergite asetose, katatergite long white setose; katatergite moreor-less flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron long white setose; metanepisternum grey pubescent, asetose, metepimeron more-or-less flat, same colour as T1, grey pubescent, long white setose.

Leg: Light brown and brown, setation white setose, brown macrosetose; pro, mes, and met coxa lightly grey pubescent, long white setose; met trochanter setose medially; femur brown, met femur more-or-less cylindrical only slightly wider than pro and mes femur, in distal half macrosetose, 1 anteroventral and 1 posteroventral row of macrosetae, posteroventrally long white, erect setose and setae arranged in distinct row; pro, mes, and met tibia straight, met tibia cylindrical, ventral keel absent, lateroposteriorly long white, erect setose and setae arranged in distinct row; pro and mes tarsomere 1 longer than tarsomere 2, but less than combined length of tarsomeres 2–3, met tarsomere 1 as long as combined length of tarsomeres 2–3; pulvillus welldeveloped, as long as well-developed claw, and as wide as base of claw; empodium absent.

Wing: Length 13.2–14.9 mm; hyaline throughout, veins light brown, microtrichia absent; cells r₁, r₄, r₅, m₃, and cup closed; C terminates at junction with R₁; R₄ terminates in R₁; R₅ terminates in R₁; stump vein (R₃) at base of R₄ present, short not reaching R₂; 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 R₁; CuA₁ and CuA₂ split proximally to m—cu (cell m₃ narrow proximally); M+CuA₁ do not terminate together in C; A₁ undulating, cell a₁ wide, A₁ and wing margin further apart proximally than distally; alula well-developed, very large and partly overlapping with scutellum medially; haltere light brown.

Abdomen: Brown; setation comprised of dense long white setose, surface entirely smooth; T1–7 brown; T1–7 long white setose; T1 apubescent, T2–7 grey pubescent; S1–7 brown; S1 asetose, S2–7 sparsely white setose; S predominantly apubescent; T2–4 parallel-sided and not constricted waist-like; bullae on T2 black, transversely elongate, surface entirely smooth, T2 surface anterior to bullae smooth.

Terminalia (Figs 7–9): Supra-hypandrial sclerite present.

Female.

Wing: Length 12.5–15.2 mm. Abdomen: Setation dense short white setose, T1 and anterior half of T2 long white setose, remaining T short white setose; bullae on T2 black, small and circular. Genitalia: 9 acanthophorite spines per plate.

Holotype: ♂ NAMIBIA: Karas: Agate Beach, 10 km N Lüderitz, 26°36′22″S 15°10′42″E, 3 m, low coastal vegetated dunes, M. and B. Irwin, 18.ii.1974 (AAM-000858, NMSA).

Paratypes: NAMIBIA: Karas: 2♀ 3♂ Agate Beach, 10 km N Lüderitz, 26°36′22″S 15°10′42″E, 3 m, low coastal vegetated dunes, M. & B. Irwin, 18.ii.1974 (AAM-000853–AAM-000857, NMSA); 1♀ 3♂ Agate Beach, 10 km N Lüderitz, 3 m, low coastal vegetated dunes, 18.ii.1974, L. Lyneborg (AAM-000861–AAM-000864, ZMUC).

Other material examined: NAMIBIA: Karas: 1♂ Khoichab Pan, 26°17′58″S 15°32′51″E, 20.i.1966 (AAM-003016, NMNW); 1♂ Diaz Point Beach, 26°38′06″S 15°05′27″E, pitfall trap, 13–26.xi.1993, E. Marais (AAM-000885, NMNW).

Type locality and distribution: Agate Beach (26°36′22″S 15°10′42″E), Namibia (Fig. 43, GBIF resource #14003). Biodiversity hotspot: inside and outside of Succulent Karoo.

Remarks: The geographic co-ordinates for the Diaz Point Beach specimen in NMNW are given as 26°37′S 15°05′E on the label, but this less-accurate position falls in the Atlantic Ocean north of the actual Diaz Point Beach.

Nothomydas: Hesse 1969: 290. Type species: Nothomydas gariepinus Hesse, 1969, by orig. des.

ZooBank LSID: see Table 1.

Diagnosis: The genus is distinguished from other Syllegomydinae by its small size with a wing length of 5.5–8.9 mm, the long proboscis that extends beyond the tip of the postpedicel, the entirely transparent wings, the slender legs, the anteriorly directed setae on abdominal tergites 4–8 in females, and structures of the male terminalia.

Description:

Male.

Abdomen and terminalia (Figs 23–34): T1–7 well-developed, entirely sclerotised, T8 posteromedially weakly sclerotised, with anterior transverse sclerotised bridge connecting lateral sclerites; T7–8 anteriorly with 2 lateral apodemes; S6 regular, without any special setation posteromedially, S8 not plate-like, medially narrow (broad laterally) and protruding ventrally (perpendicular to antero-posterior axis), not fused to T8 dorsolaterally; epandrium formed by two sclerites, separated medially and only joining anteriorly, distally in dorsal view pointed with single tip posteromedially (N. aquilonius sp. n., N. gariepinus) or pointed with bifid tip posteromedially (N. namaquensis, N. picketti sp.n.); subepandrial sclerite without lateral or median protuberances; hypandrium strongly concave, cup-shaped, entirely sclerotised ventrally (forming a single sclerite), entirely fused with gonocoxite, forming a gonocoxite-hypandrial complex, supra-hypandrial sclerite present; gonocoxite dorsoventrally flattened (same height throughout, expanded laterally and medially), without median or lateral protuberance, gonocoxal apodeme absent; 2 functional aedeagal prongs, extremely long and thin, mediodistally free, parallel or diverging laterally, distally straight or only diverging slightly laterally; aedeagal epimere present, distally simple, evenly rounded; lateral ejaculatory process absent; ejaculatory apodeme formed by single dorsoventrally oriented plate; ventro-median margin of dorsal aedeagal sheath heavily sclerotised (appearing entirely closed); dorsal aedeagal sheath long, sperm sac entirely covered; sperm sac appearing more-or-less heavily sclerotised.

Female.

Abdomen and genitalia (Fig. 22): Densely arranged anteriorly directed setae present on T3–8 and S3–8; T8 with broad anterior rectangular apodeme; T9 formed by wide, rectangular sclerite with median protuberance; T9+10 entirely fused, T10 divided into 2 heavily sclerotised acanthophorite plates, 5–6 acanthophorite spines per plate; 2 spermathecae, all equally large, formed by more-or-less expanded weakly sclerotised ducts; individual spermathecal duct long; S9 (furca) formed by 1 sclerite, ring-like (joined anteriorly and posteriorly), anterior furcal apodeme present, 2 lateral projections forming divided apodeme, lateral furcal apodeme absent, median furcal bridge absent.

ZooBank LSID: see Table 1.

Etymology: From Greek aquilonius (northern), referring to the distribution of this species representing the northernmost record of Nothomydas to date.

Diagnosis: The species, known only from a single male, is distinguished from congeners by the apubescent scutum (Fig. 35), the posteromedially grey pubescent abdominal tergites 2–7 (tergites otherwise apubescent), and the proximally grey pubescent scutellum while it is apubescent distally.

Description:

Male.

Head: Brown, in general grey pubescent; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes more-or-less horizontally straight, medially only slightly below dorsal eye margin, parafacial area less than half the width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white, covering facial gibbosity except for narrow median dorso-ventral area; frons medially apubescent, laterally grey pubescent, vertex apubescent, postgena apubescent; setation: vertex white, frons white, ocp setae white, pocl macrosetae absent; ocellar triangle apubescent; proboscis brown, long, projecting well-beyond fronto-clypeal suture and beyond tip of postpedicel; labellum small, as wide as prementum, about quarter length of prementum, unsclerotised laterally; maxillary palpus cylindrical, brown, minute.

Antenna: Brown, scape and pedicel white setose dorsally, asetose ventrally; postpedicel cylindrical in proximal half, symmetrically bulbous in distal half, ≥3.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax: Brown, predominantly apubescent; scutum uniformly brown, surface entirely smooth, apubescent, 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 present, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; postpronotal lobe brown, grey pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long white setose; scutellum grey pubescent proximally, apubescent distally, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite lightly grey pubescent, mesopostnotum asetose, anatergite asetose, katatergite long white setose; katatergite more-or-less flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron long white setose; metanepisternum lightly grey pubescent, asetose, metepimeron more-or-less flat, same colour as T1, lightly grey pubescent, long white setose.

Leg: Brown, setation predominantly white; pro, mes, and met coxa apubescent, long white setose; met trochanter setose medially; femur brown, met femur more-or-less cylindrical only slightly wider than pro and mes femur, in distal half macrosetose, 1 anteroventral and 1 posteroventral row of macrosetae, posteroventrally long white, erect setose and setae arranged in distinct row; pro, mes, and met tibia straight, met tibia cylindrical, ventral keel absent, lateroposteriorly long white, erect setose and setae arranged in distinct row; pro and mes tarsomere 1 as long as tarsomere 2, met tarsomere 1 as long as combined length of tarsomeres 2–3; pulvillus well-developed, as long as well-developed claw, and as wide as base of claw; empodium absent.

Wing: Length 7.9 mm; hyaline throughout, veins light brown, microtrichia absent; cells r₁, r₄, r₅, m₃, and cup closed; C terminates at junction with R₁; R₄ terminates in R₁; R₅ terminates in R₁; stump vein (R₃) at base of R₄ present, short not reaching R₂; 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 R₁; CuA₁ and CuA₂ split proximally to m–cu (cell m₃ narrow proximally); M₃+CuA₁ do not terminate together in C; A₁ undulating, cell a₁ wide, A₁ and wing margin further apart proximally than distally; alula well-developed; haltere light brown.

Abdomen: Brown; setation comprised of dense white setose, surface entirely smooth; T1–7 brown; T1–2 long white setose, T3–7 shorter white setose; T1 apubescent, T2–7 posteromedially grey pubescent; S1–7 brown; S1 asetose, S2–7 sparsely white setose; S predominantly apubescent; T2–4 parallel-sided and not constricted waist-like; bullae on T2 black, transversely elongate, surface entirely smooth, T2 surface anterior to bullae smooth.

Terminalia (Figs 23–25): Epandrium distally in dorsal view pointed with single tip posteromedially.

Female. Unknown.

Holotype: ♂ NAMIBIA: Karas: Rotkop, 26°42′00″S 15°23′00″E, 12–26.xi.1993, E. Marais, pitfall trap (AAM-000873, NMNW).

Type locality and distribution: Rotkop (26°42′00″S 15°23′00″E), Namibia (Fig. 43, GBIF resource #14003). Biodiversity hotspot: endemic to Succulent Karoo.

Nothomydas gariepinus: Hesse 1969: 292.

ZooBank LSID: see Table 1.

Diagnosis: The species, known only from males, is distinguished from congeners by the predominantly grey pubescent scutum (Fig. 38) with apubescent anterior slopes, the entirely grey pubescent scutellum, the only dorsally setose scape and pedicel (asetose ventrally), the partially apubescent abdominal tergite 1 (proximally apubescent and distally grey pubescent) (Fig. 38), and its apparent distribution along the Orange River valley in southern Namibia and northern South Africa (Fig. 43).

Redescription:

Male.

Head: Black, in general grey pubescent; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes more-or-less horizontally straight, medially only slightly below dorsal eye margin, parafacial area less than half the width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white, covering facial gibbosity except for narrow median dorso-ventral area; frons medially apubescent, laterally grey pubescent, vertex medially apubescent, laterally grey pubescent, postgena apubescent; setation: vertex white, frons white, ocp setae white, pocl macrosetae absent; ocellar triangle apubescent; proboscis brown, long, projecting well-beyond fronto-clypeal suture and beyond tip of postpedicel; labellum small, as wide as prementum, about quarter length of prementum, unsclerotised laterally; maxillary palpus cylindrical, brown, minute.

Antenna: Brown, scape and pedicel white setose dorsally, asetose ventrally; postpedicel cylindrical in proximal third, symmetrically bulbous in distal two-thirds, ≥5.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax: Brown, scutum predominantly grey pubescent, pleura predominantly apubescent; scutum uniformly brown, surface entirely smooth, anterior slopes (facing occiput) apubescent, otherwise densely grey pubescent with broad sublateral stripes (interrupted by transverse suture) and narrow paramedial stripes (not reaching posterior margin) sparsely grey pubescent, scutal setation comprised of long white setae with distinct rows of long dc setae and dense lateral scutal setae; dc setae pre- and postsuturally white, acr setae present, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; postpronotal lobe brown, grey pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long white setose; scutellum grey pubescent, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite grey pubescent, mesopostnotum asetose, anatergite asetose, katatergite long white setose; katatergite more-or-less flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron long white setose; metanepisternum grey pubescent, asetose, metepimeron more-or-less flat, same colour as T1, grey pubescent, long white setose.

Leg: Light brown and brown, setation brown and white; pro, mes, and met coxa apubescent, pro and mes coxa short white setose, met coxa long white setose; met trochanter setose medially; femur brown, met femur more-or-less cylindrical only slightly wider than pro and mes femur, in distal half macrosetose, 1 anteroventral and 1 posteroventral row of macrosetae, posteroventrally long white, erect setose and setae arranged in distinct row; pro, mes, and met tibia straight, met tibia cylindrical, ventral keel absent, lateroposteriorly long white, erect setose and setae arranged in distinct row; pro and mes tarsomere 1 longer than tarsomere 2, but less than combined length of tarsomeres 2–3, met tarsomere 1 less than combined length of tarsomeres 2–3; pulvillus well-developed, as long as well-developed claw, and as wide as base of claw; empodium absent.

Wing: Length 6.6–7.3 mm; hyaline throughout, veins brown, microtrichia absent; cells r₁, r₄, r₅, m₃, and cup closed; C terminates at junction with R₁; R₄ terminates in R₁; R₅ terminates in R₁; stump vein (R₃) at base of R₄ absent or only very short; 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 R₁; CuA₁ and CuA₂ split proximally to m–cu (cell m₃ narrow proximally); M₃+CuA₁ do not terminate together in C; A₁ undulating, cell a₁ wide, A₁ and wing margin further apart proximally than distally; alula well-developed; haltere light brown.

Abdomen: Brown; setation comprised of dense white and brown setose, surface entirely smooth; T1–7 brown; T1 and anterior half of T2 long white setose, remaining T2 and T3–7 brown setose; T1 grey pubescent posteromedially, T2 predominantly grey pubescent (except anterolaterally), remaining T narrowly grey pubescent medially and wider grey pubescent posteriorly; S1–7 brown; S1 asetose, S2–7 sparsely brown setose; S predominantly apubescent; T2–4 parallel-sided and not constricted waist-like; bullae on T2 black, transversely elongate, surface entirely smooth, T2 surface anterior to bullae smooth.

Terminalia (Figs 26–28): Epandrium distally in dorsal view pointed with single tip posteromedially.

Female. Unknown.

Material examined: NAMIBIA: Karas: 1♂ Rosh Pinah, 16 km S, 28°04′00″S 16°51′00″E, visiting yellow flowers Tripteris (Asteraceae), 13.x.2000, F. & S. Gess (AAM-003018, AMGS). SOUTH AFRICA: Northern Cape: 1♂ Vioolsdrif, 28°46′10″S 17°37′37″E, 4–6.x.1966, SAM Museum Staff (Holotype, SAMC).

Type locality and distribution: Vioolsdrif (28°45′22″S 17°37′13″E), Namibia, South Africa (Fig. 43, GBIF resource #14003). Biodiversity hotspot: occurring inside and outside of Succulent Karoo.

Nothomydas namaquensis: Hesse 1972: 152.

ZooBank LSID: see Table 1.

Diagnosis: The species is distinguished from congeners by the predominantly grey pubescent scutum with apubescent anterior slopes, the entirely grey pubescent scutellum, the dorsally and ventrally white setose scape and pedicel, the structure of the postpedicel, which is cylindrical in the proximal quarter and bulbous in the distal three quarters, and its apparent distribution in coastal habitats in the north-western Northern Cape Province of South Africa (Fig. 43).

Redescription:

Male.

Head: Brown, in general densely grey pubescent; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes more-or-less horizontally straight, medially only slightly below dorsal eye margin, parafacial area about as wide as half the width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white, covering entire facial gibbosity; frons medially apubescent, laterally grey pubescent, vertex medially apubescent, laterally grey pubescent, postgena apubescent; setation: vertex white, frons white, ocp setae white, pocl macrosetae absent; ocellar triangle apubescent; proboscis brown, long, projecting well-beyond fronto-clypeal suture and beyond tip of postpedicel; labellum small, as wide as prementum, about quarter length of prementum, unsclerotised laterally; maxillary palpus cylindrical, brown, minute.

Antenna: Brown, scape and pedicel white setose dorsally and ventrally; postpedicel cylindrical in proximal quarter, symmetrically bulbous in distal three-quarters, ≥6.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax: Brown, scutum predominantly grey pubescent, pleura predominantly apubescent; scutum uniformly brown, surface entirely smooth, anterior slopes (facing occiput) apubescent, otherwise grey pubescent with broad sublateral stripes (not reaching anterior margin) and narrower paramedian stripes (not reaching posterior margin) brown 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 present, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; postpronotal lobe light brown, grey pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long white setose; scutellum grey pubescent, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite grey pubescent, mesopostnotum asetose, anatergite asetose, katatergite long white setose; katatergite more-or-less flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron long white setose; metanepisternum grey pubescent, asetose, metepimeron more-or-less flat, same colour as T1, grey pubescent, long white setose.

Leg: Brown, setation white on pro and mes legs and white and brown on met leg; pro, mes, and met coxa apubescent, pro and mes coxa short white setose, met coxa long white setose; met trochanter setose medially; femur brown, met femur more-or-less cylindrical only slightly wider than pro and mes femur, in distal half macrosetose, 1 anteroventral and 1 posteroventral row of macrosetae, posteroventrally long white, erect setose and setae arranged in distinct row; pro, mes, and met tibia straight, met tibia cylindrical, ventral keel absent, lateroposteriorly long white, erect setose and setae arranged in distinct row; pro and mes tarsomere 1 longer than tarsomere 2, but less than combined length of tarsomeres 2–3, met tarsomere 1 less than combined length of tarsomeres 2–3; pulvillus well-developed on pro and mes legs, smaller on met legs; empodium absent.

Wing: Length 5.5–6.1 mm; hyaline throughout, veins brown, microtrichia absent; cells r₁, r₄, r₅, m₃, and cup closed (r₅ sometimes open); C terminates at junction with M₁ (or M₁+M₂) or terminates at junction with R₁; R₄ terminates in R₁; R₅ terminates in R₁; stump 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 or R₁; CuA₁ and CuA₂ split proximally to m—cu (cell m₃ narrow proximally); M₃+CuA₁ do not terminate together in C; A₁ undulating, cell a₁ wide, A₁ and wing margin further apart proximally than distally; alula well-developed; haltere light brown.

Abdomen: Brown; setation comprised of dense white and brown setose, surface entirely smooth; T1–7 brown; T1 and anterior half of T2 long white setose, remaining T2 and T3–7 brown setose; T1 apubescent, T1–7 anterior 0.25 and laterally apubescent, remaining T grey pubescent; S1–7 brown; S1 asetose, S2–3 white and brown setose; S mainly apubescent; T2–4 parallel-sided and not constricted waist-like; bullae on T2 black, transversely elongate, surface entirely smooth, T2 surface anterior to bullae smooth.

Terminalia (Figs 29–31): Epandrium distally in dorsal view pointed with bifid tip posteromedially.

Female.

Head: Mystax white, covering facial gibbosity except for narrow median dorso-ventral area. Antenna: Brown; scape and pedicel white setose dorsally and ventrally; postpedicel cylindrical in proximal quarter, symmetrically bulbous in distal three-quarters, ≥6.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel. Leg: Setation predominantly white; in distal half macrosetose, 1 anteroventral row of macrosetae. Wing: Length 6.1 mm; veins light brown; C terminates at junction with R₁; M₁ (or M₁+M₂) terminates in R₁. Abdomen: Scattered white setose, T1 and anterior quarter of T2 long white setose, remaining tergites short white setose, setae directed anteriorly on T3–7; S1 asetose, S2–7 sparsely white setose. Genitalia (Fig. 22): 5–6 acanthophorite spines per plate.

Material examined: SOUTH AFRICA: Northern Cape: 1♀ 5♂ Port Nolloth, 29°15′17″S 16°52′18″E, x.1964, SAM Museum Staff (holotype & paratypes, SAMC).

Type locality and distribution: Port Nolloth (29°15′17″S 16°52′18″E), South Africa (Fig. 43, GBIF resource #14003). Biodiversity hotspot: endemic to Succulent Karoo.

ZooBank LSID: see Table 1.

Etymology: The species is named after and dedicated to the memory of Vespidae systematist and taxonomist and good friend Kurt Milton Pickett who left us much too early (Crowley 2011).

Diagnosis: The males of this species are distinguished from congeneric males by the apubescent scutum, the predominantly apubescent abdominal tergites 1–5 while tergites 6–7 are entirely grey pubescent (Fig. 41), and the entirely apubescent scutellum. The females can be distinguished by the entirely grey pubescent vertex and the predominantly grey pubescent abdominal tergites 2–4 (only anterolaterally apubescent) while tergites 6–7 are apubescent (Fig. 42).

Description:

Male.

Head: Black, in general densely grey pubescent; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes more-or-less horizontally straight, medially only slightly below dorsal eye margin, parafacial area about as wide as half the width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white, covering entire facial gibbosity; frons medially apubescent, laterally grey pubescent, vertex apubescent, postgena apubescent; setation: vertex white or yellow, frons white, ocp setae white or yellow, pocl macrosetae absent; ocellar triangle apubescent; proboscis brown, long, projecting well-beyond fronto-clypeal suture and beyond tip of postpedicel; labellum small, as wide as prementum, about quarter length of prementum, unsclerotised laterally; maxillary palpus cylindrical, brown, minute.

Antenna: Brown, scape and pedicel white setose dorsally, asetose ventrally; postpedicel cylindrical in proximal third, symmetrically bulbous in distal two-thirds, ≥4.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel.

Thorax: Brown, predominantly apubescent; scutum uniformly brown, surface entirely smooth, apubescent, 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 present, lateral scutal setae white, npl setae 0, spal setae 0, pal setae 0; postpronotal lobe brown, grey pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long white setose; scutellum apubescent, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite apubescent, mesopostnotum asetose, anatergite asetose, katatergite long white setose; katatergite more-or-less flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron long white setose; metanepisternum lightly grey pubescent, asetose, metepimeron more-or-less flat, same colour as T1, lightly grey pubescent, long white setose.

Leg: Brown, setation predominantly white; pro, mes, and met coxa apubescent, long white setose; met trochanter setose medially; femur brown, met femur more-or-less cylindrical only slightly wider than pro and mes femur, in distal half macrosetose, 1 anteroventral and 1 posteroventral row of macrosetae, posteroventrally long white, erect setose and setae arranged in distinct row; pro, mes, and met tibia straight, met tibia cylindrical, ventral keel absent, lateroposteriorly long white, erect setose and setae arranged in distinct row; pro and mes tarsomere 1 longer than tarsomere 2, but less than combined length of tarsomeres 2–3, met tarsomere 1 less than combined length of tarsomeres 2–3; pulvillus well-developed, as long as well-developed claw, and as wide as base of claw; empodium absent.

Wing: Length 7.0–7.4 mm; hyaline throughout, veins brown, microtrichia absent; cells r₁, r₄, r₅, m₃, and cup closed; C terminates at junction with R₁; R₄ terminates in R₁; R₅ terminates in R₁; stump vein (R₃) at base of R₄ present, short not reaching R₂; 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 R₁; CuA₁ and CuA₂ split proximally to m—cu (cell m₃ narrow proximally); M₃+CuA₁ do not terminate together in C; A₁ undulating, cell a₁ wide, A₁ and wing margin further apart proximally than distally; alula well-developed; haltere light brown.

Abdomen: Brown; setation comprised of dense white setose, surface entirely smooth; T1–7 brown; T1–2 long white setose, T3–7 shorter white setose; T1–5 apubescent, T6–7 entirely grey pubescent; S1–7 brown; S1 asetose, S2–7 sparsely white setose; S predominantly apubescent; T2–4 parallel-sided and not constricted waist-like; bullae on T2 black, transversely elongate, surface entirely smooth, T2 surface anterior to bullae smooth.

Terminalia (Figs 32–34): Epandrium distally in dorsal view pointed with bifid tip posteromedially.

Female.

Head: Vertex entirely grey pubescent; setation: vertex white, ocp setae white. Antenna: Brown; scape and pedicel white setose dorsally, asetose ventrally; postpedicel cylindrical in proximal third, symmetrically bulbous in distal two-thirds, ≥5.0× as long as combined length of scape and pedicel; apical ‘seta-like’ sensory element situated apically in cavity on postpedicel. Thorax: Scutum predominantly grey pubescent, pleura predominantly apubescent; anterior slopes (facing occiput) apubescent, otherwise densely grey pubescent with broad sublateral stripes (not reaching anterior margin) and narrower paramedian stripes (not reaching posterior margin) sparsely grey pubescent (or even apubescent); scutellum grey pubescent proximally, apubescent distally, asetose; mesopostnotum, anatergite, and katatergite grey pubescent. Leg: pro, mes, and met coxa apubescent, pro and mes coxa short white setose, met coxa long white setose; pro and mes tarsomere 1 as long as tarsomere 2. Wing: Length 8.0–8.9 mm; veins light brown. Abdomen: Scattered white setose; T1 and anterior half of T2 long white setose, remaining T2 and T3 short white setose; T1 apubescent, T2–4 predominantly grey pubescent, anterolaterally apubescent, T5 grey pubescent medially, T6–7 apubescent. Genitalia: 6 acanthophorite spines per plate.

Holotype: ♂ NAMIBIA: Karas: Skerpioenkop,27°46′00″S 16°29′58″E, 20–22.ix.1997, A. Kirk-Spriggs & E. Marais, yellow trays (AAM-000878, NMNW).

Paratypes: 4♀ 1♂ same data as holotype (AAM-000874–AAM-000877, AAM-000879, NMNW).

Type locality and distribution: Skerpioenkop (27°46′00″S 16°29′58″E), Namibia (Fig. 43, GBIF resource #14003). Biodiversity hotspot: endemic to Succulent Karoo.

Remarks: N. picketti sp. n. is the most sexually dimorph species within this genus as can be seen from the rather long description of the female and that the male and female are separated in the identification key.