Parectyphus namibiensis Hesse, 1972

Lyons, Kathleen M. & Dikow, Torsten, 2010, Taxonomic revision of Ectyphus Gerstaecker, 1868 and Parectyphus Hesse, 1972 with a key to world Ectyphinae (Insecta, Diptera, Mydidae), ZooKeys 73, pp. 25-59 : 44-49

Parectyphus namibiensis Hesse, 1972 Figs 26-28, 30384445

Parectyphus namibiensis Hesse 1972: 165; Bowden 1980: 326.

Diagnosis:

See above for generic diagnosis.

Re-description male:

Head: black, facial gibbosity light brown, rarely black, in general rarely predominantly apubescent, yellow pubescent on median eye margin; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes slightly depressed, parafacial area very narrow, facial gibbosity nearly touching median eye margin; facial gibbosity distinct, well-developed and discernible in lateral view; mystax white, covering entire facial gibbosity, rarely yellow, covering entire facial gibbosity; frons predominantly apubescent, vertex medially apubescent, laterally grey pubescent, rarely medially apubescent, laterally yellow pubescent, postgena lightly silver pubescent; setation: vertex white, rarely yellow, frons white, rarely yellow, ocp setae white, rarely yellow, pocl setae white, rarely yellow; ocellar triangle apubescent; proboscis brown, long, projecting beyond fronto-clypeal suture; labellum small, as wide as prementum, as long as prementum, unsclerotised laterally; maxillary palpus cylindrical, brown, about ½ length of proboscis.

Antenna: brown, scape and pedicel brown setose dorsally and ventrally; postpedicel cylindrical in proximal ½, symmetrically bulbous in distal ½, ≥ 4.0 times as long as combined length of scape and pedicel, rarely ≥ 6.0 times as long as combined length of scape and pedicel; apical ‚seta-like‘ sensory element situated apically in cavity on postpedicel.

Thorax: brown, rarely dark brown to bluish-black, scutum predominantly grey pubescent, pleura predominantly apubescent, rarely predominantly yellow pubescent; scutum medially bluish-black, laterally brown, surface entirely smooth, lightly grey pubescent, rarely lightly yellow pubescent, paramedial stripes (merging postsuturally) and posterior lateral stripes densely yellow pubescent, scutal setation comprised of scattered short white, sometimes black, setae with distinct rows of long dorsocentral setae and lateral scutal setae; dc setae pre- and postsuturally white, rarely pre- and postsuturally black, acr setae present, lateral scutal setae white, rarely black, npl, spal, and pal setae absent; postpronotal lobe light brown, partly silver pubescent, rarely dark brown, partly yellow pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long brown setose, rarely long black setose; scutellum lightly grey pubescent, long white setose, rarely lightly grey pubescent, long black setose, apical scutellar setae present; mesopostnotum, anatergite, and katatergite grey pubescent, rarely lightly yellow pubescent, mesopostnotum asetose, anatergite long black setose or long white setose, katatergite asetose; katatergite elevated and smoothly convex; anterior anepisternum asetose, supero-posterior anepisternum long white setose, rarely long black setose; posterior anepimeron long black setose or long white setose, katepimeron asetose; metepimeron evenly elevated, same colour as T1, apubescent, asetose, rarely silver pubescent, asetose; metepisternum silver pubescent, asetose.

Leg: brown, setation black and white; pro coxa apubescent, long black setose, mes coxa lightly silver pubescent, long white and black setose, rarely apubescent, long black setose, met coxa lightly silver pubescent, long white and black setose, rarely apubescent, long black setose; met trochanter setose medially or macrosetose medially; femur brown, met femur evenly clubbed in distal ¾, in distal ½ macrosetose, 1 antero-ventral and 1 postero-ventral row of macrosetae; pro, mes, and met tibia straight, met tibia cylindrical with distinct ventral keel terminating into a sharp spine; pro and mes tarsomere 1 about as long as individual tarsomeres 2, 3, or 4, met tarsomere 1 slightly longer than tarsomere 2, tarsomeres 1 and 2 longer than tarsomeres 3 and 4 combined; pulvillus well-developed, as long as well-developed claw, and as wide as base of claw; empodium absent.

Wing: length = 13.5-15.5 mm; generally hyaline, sometimes slightly brown stained along veins, veins light brown, microtrichia absent; cells r1, r4, r5, m3, + cup closed; C well-developed, around entire wing; R4 terminates in R1; R5 terminates in R1; stump vein (R3) at base of R4 present, long and connecting R4 and 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 C; CuA1 and CuA2 split proximally to m-cu (cell m3 narrow proximally); M3+CuA1 terminate together in C; A1 undulating, cell a1 wide, A1 and wing margin further apart proximally than distally; alula well-developed; halter light brown, rarely brown.

Abdomen: brown to bluish-black; setation comprised of scattered white and black setae, surface microrugose; T1-7 brown, rarely dark brown with narrow light brown posterior margin; T1 long white setose, T2-3 short black setose, rarely T1 long black setose, T2-3 short black setose; T predominantly apubescent; S1 light brown, S2-7 light brown with narrow yellow posterior margin, rarely S1-7 brown; S1 asetose, S2-3 short black 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;.

Male terminalia: T1-7 well-developed, entirely sclerotised, T8 postero-medially weakly sclerotised, with anterior transverse sclerotised bridge connecting lateral sclerites; T7-8 anteriorly with 2 lateral apodemes; S6 regular, without any special setation postero-medially, S8 well-developed and simple, fused to T8 dorso-laterally, entire (undivided) ventro-medially; epandrium formed by single sclerite (fused medially ± entirely), pointed postero-laterally; subepandrial sclerite without lateral or median protuberances; hypandrium ± flat, rectangular to square sclerite, entirely fused with gonocoxite, forming a gonocoxite-hypandrial complex; gonocoxite dorso-ventrally flattened in distal ½, higher in proximal ½, with palp-like lateral appendage, gonocoxal apodeme present, short (at most slightly extending hypopygium anteriorly); 1 functional aedeagal prong, aedeagal epimere absent; lateral ejaculatory process absent; ejaculatory apodeme formed by single dorso-ventrally 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 ± heavily sclerotised.

Description female:

Head: in general yellow pubescent; mystax black, covering entire facial gibbosity; frons yellow pubescent, vertex medially apubescent, laterally yellow pubescent; setation: vertex black, frons black, ocp setae black, pocl setae black.

Antenna: postpedicel ≥ 5.0 times as long as combined length of scape and pedicel.

Thorax: light brown, predominantly yellow pubescent; scutum medially brown, laterally dark yellow, surface entirely smooth, lightly yellow pubescent, anterior paramedial and lateral stripes densely yellow pubescent; dc setae pre- and postsuturally black, acr setae present, rarely absent; lateral scutal setae black; postpronotal lobe light brown, partly white pubescent; proepisternum, lateral postpronotum, and postpronotal lobe long black setose; scutellum lightly grey pubescent, long black setose; mesopostnotum, anatergite, and katatergite lightly yellow pubescent, mesopostnotum asetose, anatergite long black setose; supero-posterior anepisternum long black setose; posterior anepimeron long black setose; metepimeron same colour as T1, lightly silver pubescent, asetose; metepisternum silver pubescent, asetose.

Leg: brown and yellow, setation predominantly black; pro, mes, and met coxa apubescent, long black setose; met trochanter macrosetose medially; femur brown, met femur yellow; 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.

Wing: length = 12.8-14.2 mm; slightly brown stained throughout; halter light brown.

Abdomen: brown; setation comprised of dense short black setae; T1 brown, yellow medially, T2-7 brown with narrow dark yellow anterior and posterior margin, rarely T1-7 yellow, brown postero-laterally; T1-3 densely black setose; S1 light brown, S2-7 light brown with narrow yellow posterior margin.

Female genitalia: densely arranged anteriorly directed setae present on T7-8 and S7-8; 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, 8 acanthophorite spurs per plate; 3 spermathecae, all equally large, formed by ± expanded weakly sclerotised ducts; individual spermathecal duct long; S9 (furca) formed by 2 sclerites, separated anteriorly and posteriorly, anterior furcal apodeme present, 2 lateral projections forming divided apodeme, lateral furcal apodeme absent, median furcal bridge absent.

Material examined:

Namibia: Erongo Region: 1♂ Gobabeb, 23°33'37"S; 15°02'26"E, 408 m, -.-.- (holotype, SMNS); Karas Region: 1♀ Kanaän 104, 25°50'42"S; 16°09'30"E, 6-7.x.1972, (AAM-003505, NMNW); 1♂ Klinghardt Mountains, 27°20'00"S; 15°45'00"E, 1.x.1982, V. Whitehead (AAM-003486, SAMC); 1♂ Klinghardt Mountains, 24.x.1977, V. Whitehead (AAM-003485, SAMC); 1♂ N amuskluft 88, 27°48'00"S; 16°52'00"E, 7-14.x.1970 (AAM-003504, SAMC); 3♀ 1♂ Rosh Pinah, 10 km NW, 27°54'00"S; 16°42'00"E, 13.viii.1990, C. Roberts E. Marais (AAM-003606-AAM-003609, NMNW); South Africa: Northern Cape Province: 2♀ Tnong-Gys Dunes, 29°32'50"S; 17°14'03"E, 23-25.ix.1988, J. Irish E. Marais (AAM-003506-AAM-003507, NMNW).

Type locality, distribution, and biodiversity hotspot:

Gobabeb (23°33'37"S; 15°02'26"E), Erongo, Namibia. Namibia and South Africa. Succulent Karoo biodiversity hotspot.

Remarks:

Prior to this study, Parectyphus namibiensis was only known from the ♂ holotype collected at Gobabeb (Fig. 45). The location of new Parectyphus specimens in two museum collections has allowed us to describe the female for the first time and also to observe a considerable amount of colour variation among the 11 studied specimens. We dissected the ♂ terminalia from all localities, if available, to verify whether there is morphological variation in these generally species-specific features. However, we were unable to detect any differences and therefore concluded that all specimens represent Parectyphus namibiensis albeit coming from isolated collecting events (Fig. 45). The type locality, which marks the northern-most record, is some 700 km separated from the Tnong-Gys dunes in north-western South Africa as the southern-most record. While the holotype is entirely white setose (Fig. 39, 42), the specimens from the Klinghardt Mountains and Namuskluft, in the centre of the currently known distribution, are yellow setose (Fig. 40-41, 43) and the specimens from Rosh Pinah and Tnong-Gys dunes in the south are black setose (Fig. 44). The pubescence pattern on the scutum is in several instances very difficult to observe and since most specimens we studied were caught in wet Malaise traps, the coloration of the entire body might also differ among populations. Although Hesse (1972) observed an absence of macrosetae on the metathoracic trochanters of the holotype, the other specimens studied by us exhibit macrosetae, which is consistent with the delimitation of Ectyphinae as having macrosetose metathoracic trochanters (e.g., Wilcox and Papavero 1971), which separates this taxon from other Mydidae taxa. As mentioned under Ectyphus armipes , there are three specimens of this species known from Tongaat on the KwaZulu-Natal coast of South Africa in which the particular wing venation of Parectyphus , namely the stump vein (R3) entirely connecting R2 and R4 (Fig. 38), is also found. Parectyphus namibiensis exhibits other characteristics not found among Ectyphus species, e.g., the configuration of the male terminalia and the shape of the furca and spermathecae in the females, and therefore we do not propose to synonymise both genera. A comprehensive phylogenetic analysis of Mydidae , including all Ectyphinae , genera currently in preparation by the second author, will shed light on this question and establish whether Ectyphus and Parectyphus are adelphotaxa or whether Parectyphus is just an apomorphic Ectyphus .