Syllegomydas Syllegomydas elachys, Dikow, Torsten, 2010

Dikow, Torsten, 2010, New species and new records of Mydidae from the Afrotropical and Oriental regions (Insecta, Diptera, Asiloidea), ZooKeys 64, pp. 33-75 : 52-55

Syllegomydas Syllegomydas elachys sp. n. Figs 24 –2638– 394448

Etymology:

elachys Greek adjective = little, small. Referring to the small size of this species.

Diagnosis:

The species is distinguished from congeners by the very small size, the entirely grey pruinose abdominal tergites, the overall light brown coloration in females, the relatively short antennae, the very short proboscis, the parallel longitudinal ridges on the bullae, the presence of lateral furcal apodemes in females, and its apparent distribution in northern Zimbabwe.

Description Male:

Head: brown, in general densely grey pruinose; width distinctly greater than thorax, interocular distance on vertex larger than at ventral eye margin, vertex between compound eyes ± horizontally straight, medially only slightly below dorsal eye margin, parafacial area more than ½ the width of central facial gibbosity; facial gibbosity distinct, well-developed and discernible in lateral view; mystax light brown, covering entire facial gibbosity or white, covering entire facial gibbosity; frons entirely grey pruinose, vertex entirely grey pruinose, postgenae apruinose or lightly silver pruinose; setation: vertex light brown or white, frons light brown or white, ocp setae white, pocl setae white; ocellar triangle apruinose; proboscis light brown, very short, vestigial, knob-like; labella small, as wide as prementum, only forming distal tip of proboscis, unsclerotised laterally; maxillary palpi cylindrical, light brown, slightly longer than proboscis.

Antenna: brown or orange, 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; apical ‚seta-like‘ sensory element situated apically in cavity on postpedicel.

Thorax: brown, predominantly grey pruinose; scutum medially bluish-black, laterally brown, surface entirely smooth, predominantly grey pruinose, asetose median and sublateral stripes sparsely grey pruinose, setose areas densely grey pruinose, scutal setation comprised of distinct rows of long dorsocentral setae and lateral scutal setae; dc setae pre- and postsuturally white, acr setae absent, lateral scutal setae white, npl, spal, and pal setae absent; postpronotal lobe light brown, grey pruinose; proepisternum, lateral postpronotum, and postpronotal lobes long white setose; scutellum entirely grey pruinose, asetose, apical scutellar setae absent; mesopostnotum, anatergite, and katatergite grey pruinose, mesopostnotum asetose, anatergite long white setose, katatergite long white setose; katatergite ± flat; anterior anepisternum asetose, supero-posterior anepisternum long white setose; posterior anepimeron long white setose, katepimeron white setose; metepimeron ± flat, same colour as T1, grey pruinose, long white setose; metepisternum grey pruinose, asetose.

Leg: light brown or yellow, setation predominantly white; all coxae grey pruinose, white setose; met trochanter setose medially; femora brown or light brown, met femora ± cylindrical only slightly wider than pro and mes femora, in distal ½ macrosetose, 1 antero-ventral and 1 postero-ventral row of macrosetae; all tibiae laterally arched, met tibia cylindrical, ventral keel absent; pro and mes tarsomere 1 as long as combined length of tarsomeres 2-3, met tarsomere 1 as long as combined length of tarsomeres 2-4; pulvilli well-developed, as long as well-developed claws, and as wide as base of claws; empodium absent.

Wing: length = 5.6-7.5 mm; hyaline throughout, veins light brown, microtrichia absent; cells r1, r4, r5, m3, + cup closed; C terminates at junction with R1; R4 terminates in R1; R5 terminates in R1; stump vein ( R 3) at base of R4 present, short not reaching R2; R4 and R5 ± parallel medially; r-m distinct, R4+5 and M1 apart, connected by crossvein; M1 straight at r-m (not curving anteriorly), M1 (or M 1+ M 2) 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; halter light brown.

Abdomen: brown; setation comprised of scattered white setae, surface entirely smooth; T1-7 brown, yellow posterior margins; T1 and anterior ¼ of T2 long white setose, remaining T2 and T3 brown and white setose; T entirely grey pruinose; S1-7 brown; S1 asetose, S2-3 sparsely yellow setose; S entirely grey pruinose; T2-4 parallel-sided and not constricted waist-like; bullae on T2 brown, transversely elongate, surface with parallel longitudinal ridges, T2 surface anterior to bullae smooth.

Male terminalia: T1-8 well-developed; T7-8 anteriorly with 2 lateral apodemes; S6 regular, without any special setation postero-medially, S8 well-developed and simple, not fused to T8 dorso-laterally, entire (undivided) ventro-medially; epandrium formed by single sclerite (fused medially ± entirely), rounded postero-laterally; 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; gonocoxites dorso-ventrally flattened in distal ½, higher in proximal ½, without median or lateral protuberance, gonocoxal apodeme absent; 2 functional aedeagal prongs, short and wide, medio-distally free, parallel or diverging laterally, distally straight or only diverging slightly laterally; aedeagal epimere present, distally simple, evenly rounded; lateral ejaculatory processes 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: brown, facial gibbosity light brown; parafacial area about as wide as ½ the width of central facial gibbosity.

Antenna: postpedicel ≥ 3.0 times as long as combined length of scape and pedicel.

Thorax: scutum uniformly brown; proepisternum, lateral postpronotum, and postpronotal lobes short white setose; anatergite short white setose; katatergite short white setose; supero-posterior anepisternum asetose; posterior anepimeron short white setose.

Leg: brown, setation brown and white; all coxae grey pruinose, brown setose; pro and mes tarsomere 1 longer than tarsomere 2, but less than combined length of tarsomeres 2-3.

Wing: length = 8.9-9.2 mm; slightly brown stained throughout, veins brown; halter brown.

Abdomen: setation comprised of sparsely scattered short brown setae, T1-7 brown; T1-3 sparsely brown setose; T predominantly apruinose; S1-3 asetose; S predominantly apruinose; bullae on T2 light brown, transversely elongate.

Female genitalia: densely arranged anteriorly directed setae absent, only few 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, 5-7 acanthophorite spurs per plate; 2 spermathecae, all equally large, formed by ± expanded weakly sclerotised ducts and spherical weakly sclerotised reservoirs; individual spermathecal ducts short; 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 present, median furcal bridge absent.

Material examined:

Zimbabwe: Mashonaland East: 1 ♂ Kotwa, Broken Causeway , 17°03'00"S; 032°46'00"E, 7.ix.1986, M. Lillig S. Potel ( AAM-001111 paratype, ZSMC) ; 1 ♂ Kotwa, Broken Causeway , 8.ix.1986, M. Lillig S. Potel ( AAM-001112 paratype, ZSMC) ; 1 ♂ Kotwa, Broken Causeway , 31.viii.1986, M. Lillig S. Potel ( AAM-001113 paratype, ZSMC) ; 1 ♂ Kotwa, Broken Causeway , 25.viii.1986, M. Lillig S. Potel ( AAM-001114 paratype, ZSMC) ; 1 ♀ Kotwa, Chimana Causeway , 17°06'00"S; 032°38'00"E, 26.viii.1986, M. Lillig S. Potel ( AAM-001115 paratype, ZSMC) ; Mashonaland West: 1 ♀ 3 ♂ Rukommetje Research Station , 16°06'00"S; 029°15'00"E, -. viii.1988, J. Weyrich ( AAM-001117 1 ♂ holotype, AAM-001116 , AAM-001118-AAM-001119 paratypes, ZSMC) ; 1 ♂ Rukommetje Research Station , -. viii.1988, J. Weyrich ( AAM-001120 paratype, ZSMC) ; 4 ♂ SE Angwe Bridge , 16°05'00"S; 030°09'00"E, -. viii.1988, J. Weyrich ( AAM-001121-AAM-001124 paratypes, ZSMC) .

Type locality and distribution:

Rukommetje Research Station (16°06'00" S; 029°15'00" E), Zimbabwe (Fig. 48). Biodiversity hotspot/high-biodiversity wilderness area: -/Miombo-Mopane Woodlands and Savannas.

Remarks:

This species does not belong to the subgenus Notobates as defined by Hesse (1969: 274) and it might therefore present the southernmost distribution of the primarily Palaearctic subgenus Syllegomydas . The monophyly of Syllegomydas (Notobates) needs to be investigated and will be tested with a phylogenetic study of Mydidae currently in preparation by the author.