Afroxanthandrus conopeum, Midgley & Goergen & Jordaens, 2024

Midgley, John M., Goergen, Georg & Jordaens, Kurt, 2024, A revision of the Afrotropical hover fly genus Afroxanthandrus Kassebeer, 2000 (Diptera, Syrphidae), with the description of two new species and one new synonymy, European Journal of Taxonomy 968, pp. 60-85 : 74-78

Afroxanthandrus conopeum sp. nov.

urn:lsid:zoobank.org:act:23AB5783-35B3-45B9-B0BD-23EE2DE87FF3

Figs 1 , 4 , 9 , 15 , 22–24

Diagnosis

Differs from A. congensis and A. longipilus in having broad yellow fasciae on tergites 2 and 3 which occupies almost the entire tergite ( A. congensis with a narrower, curved yellow fascia which occupies at most half of tergites 2 and 3, A. longipilus with a narrow, curved fascia on tergite 2 occupying at most half of the tergite, and with a narrow, straight fascia on tergite 3 which occupies at most one third of the tergite) and from A. comorosensis sp. nov. in having tergite 4 with a narrower fascia than on tergite 3 (fasciae of equal width in A. comorosensis ). Surstyli extremely elongated, eight times as long as wide (2 to 2.5 times as long as wide in A. comorosensis and A. congensis )

Etymology

Named for the canopy inhabiting behaviour observed in this species. To be treated as a noun in apposition.

Type material examined

Holotype

SOUTH AFRICA • ♂; KwaZulu-Natal, Giant’s Castle Nature Reserve , Main caves forest; 29.271814 S, 29.526489 E; 30 Jan. 2023; K. Jordaens, J. Midgley and T. Bellingan leg.; NMSA, NMSA-Dip 219971 .

Paratypes

MALAWI • 1 ♂; Southern Region, Zomba Plateau Mountain Road ; elev. 1400 m; 5 Oct. 1998; F. Kaplan and A. Freidberg leg. USNM, USNMENT 01842997 .

SOUTH AFRICA – KwaZulu-Natal • 1 ♂; Croc Velley Nature Reserve near Sheffield Beach ; 29°28′37″ S, 31°15′04″ E; elev. 60 m; 12 Jun. 2001; J.G.H. Londt leg.; in patch of swamp forest; NMSA, NMSA-Dip 064762 • 1 ♂; Karkloof , Shawswood Forest; 29.306404 S. 30.303695 E; 13 Nov. 2018; J. Midgley, K. Williams and K. Jordaens leg.; NMSA, NMSA-Dip 086808 • 1 ♂; same data as for preceding; AB48930365, GenBank: PP828580 ; NMSA, NMSA-Dip 086809 • 1 ♂; same data as for preceding; AB48930348 GenBank: PP828579 ; NMSA, NMSA-Dip 086826 . – Western Cape • 1 ♂; Groenkop forest ; 29 Jan. 2022; R. Swart leg.; collected from flowers of Curtisia dentata ; RMCA, RMCA ENT 000056904 .

Description

MEASUREMENTS. Body: 9.2–10.1 mm; wing: 7.1–8.0 mm.

Male

HEAD ( Fig. 4 ). Black, with medium facial tubercle and a medium sized antennal prominence. Face straight in profile; parallel sided, approximately 30% of the maximum head width; covered with dense, yellowish-white pollinosity, completely obscuring the black ground colour, thinner pollinosity on the oral margin and gena, facial tubercle bare; with medium to long, light yellowish pilosity, medial region bare from oral margin to antennal base. Frons with dense yellowish-white pollinosity, reaching from the eye contiguity to the base of the antennal prominence. The antennal prominence and lunule are bare, the lunule orange in ground colour, the prominence dark brown to black. Frons with medium to long, light yellow pilosity, lunule and antennal tubercle bare. Vertical triangle with some dark brown pilosity anteriorly, 2–3 times the width of the anterior ocellus, with a few longer, golden brown pili anteriorly and a dense patch of long pile posteriorly; vertex elongated, narrow, angle at eye contiguity approximately 30°; ocellar triangle acutely angled, clearly raised, anterior ocellus round, posterior ocelli oval, about 1.5 times as long as wide. Occiput with pale brown to dark yellow pilosity dorsally, white laterally, thin dorsally but broad and scale like laterally, with pale yellow white pollinosity. Eyes bare, kidney-shaped in lateral view. Frontal ommatidia slightly enlarged only in a small area above the antennae. Antennae orange-brown, paler basally; elongate, slightly longer than the maximum width of the face, narrow, rounded apically, on dorsal side pedicel about the same length as the scape, postpedicel 2.5 times the length of the pedicel. Scape and pedicel orange basally and darker apically, with short to medium, thick, dark brown pilosity, postpedicel dark, with sparse pollinosity but no pilosity. Arista bare, inserted basally, about 1.2 times the length of the postpedicel.

THORAX ( Fig. 9 ). Scutum evenly rounded, except for a small raised oval bump on each side, anterior to the suture; dark brown to black, postalar callus paler brown, postalar callus brown pilosity. Pilosity long, slightly longer and much denser laterally, golden brown, each pilus on a small, rounded, raised, non-pollinose base. Scutal pollinosity densest between the suture and postpronotum and along the suture, a less dense pollinosity forms a wide strip in front of the scutellum and across the anterior half of the scutum, light yellow-brown; sparse on the remainder of the scutum. Scutellum very broad and large, ~60% the width and ~40% the length of the scutum; dark brown to black; pilosity denser than on the scutum, the density of the raised bases making the surface rough and the margin appear serrated; base narrowly bare, smooth; with a long, multi-rowed, yellowish brown subscutellar fringe. Pleura dark brown to black; evenly rounded except for a moderate bulge on the posterolateral anepisternum; yellow to white pollinose, most dense on the posterior anepisternum, katepisternum, meron, and katepimeron; pilosity yellowish brown, long, bases smaller than on scutum, longer on dorsal posterior anepisternum. Dense pilosity limited to patches on the posterior anepisternum, anepimeron, katepisternum, the katatergite, scattered pilosity on the katepimeron. Metasternum bare. Plumule brownish anteriorly, yellow posteriorly.

LEGS. Hind coxa with a distinct tuft of pile at posteromedian angle, with scattered long, brown and yellow-white pile on the anterior surface, mid coxa with scattered, yellowish brown pile. Fore coxa with a few, yellow-white pili on medial distal margins. Trochanters with yellowish pile. Fore and mid femur brown with small pale (white to yellow) sections at the base and apex, hind femur dark brown, with white to yellow basal section and lighter brown ventrodistal section, fore femur curved, mid femur with a slight medial swelling, hind femur swollen in distal two thirds. Fore femur with short, yellowish brown pile, mid femur with long pile basally, longer than width of the femur, gradually shorter distally, at apex less than half the width of the femur, pile yellow-brown basally, brown distally, hind femur covered with a mix of short and long pile, yellowish on pale parts of the femur, brown on darker parts. Fore tibia pale yellow, mid tibia yellowish white, hind tibia orange in basal 2/5, brown distally. Fore and mid tibiae with short, yellow-white pile, hind tibia with short, dark brown pile on most of the surface, longer on anterior surface. Fore tarsus brown. Mid tarsus with two yellowish basal segments and three brown apical segments. Hind tarsus brown. All tarsi with brown pile, paler dorsobasally on fore and mid tarsi.

WINGS. Extensively microtrichose in apical part, bare patches at base of cells c, r 1, dm, cup. Alula entirely microtrichose. Cell bm extensively bare, but with a small dense patch of microtrichia in the distal region, in line with the knot of the spurious vein. Cell br mostly bare, but with some microtrichia anterior to and distal of the knot of the spurious vein. Cell cua extensively bare, with some microtrichia centrally. Calypters yellow to orange, darker dorsally, with fringe of long yellowish orange pile. Halteres whitish.

ABDOMEN ( Fig. 15 ). Elongate, broadly oval, though tergite 2 parallel sided. Shorter than the wings, about as wide as or slightly broader than the thorax. Tergite 1 yellow, with a thin dark brown posterior border; tergite 2 yellowish white basally, gradually becoming yellow then orange, posteriorly with small brown maculae that become denser and form a brown band on the posterior margin. Lateral margins of tergite 2 thinly yellow, joining with the main yellow marking anteriorly. Tergite 3 orange, with thin brown posterior border. Tergite 4 orange with broad brown posterior border, occupying about half the length of tergite 4. Tergite 5 brown. Tergite 2 slightly longer than tergite 3, tergite 3 and tergite 4 the same length and tergite 5 small, about ¼ the length of tergite 4. Pile numerous but short, light brown centrally and yellow laterally, somewhat longer lateral to tergite 1 and basolateral to tergite 2. Sternite 1 white, sternite 2 white anteriorly, faintly yellow near posterior edge, sternite 3 pale yellow, sternite 4 orange brown, sternite 5 onwards to the genitalia dark brown. Short white pile on sternites 1–2, yellowish on posterior sternites.

MALE GENITALIA ( Figs 22–23 ). Large (1.2 mm long). Superior lobes projecting inwards, about half as long as surstyli, strongly curved in dorsal view, rounded apically in lateral view. Surstyli extremely elongated, about 8 times as long as wide, rounded apically and covered in small hairs. Hypandrium projects past superior lobes.

Female

Unknown.

Distribution

Known from Malawi and South Africa (KwaZulu-Natal and Western Cape provinces).

Remarks

This species has been collected from indigenous forest patches (Southern Afrotemperate Forest, FOz1; Southern Mistbelt Forest, FOz3; Northern Coastal Forest, FOz7 ( Mucina & Rutherford 2006)). One specimen was collected from flowers of Curtisia dentata (Burm.f.) C.A.Sm. ( Cornaceae ) in the forest canopy.

Figures

Fig. 1. Map of the known distribution of species of Afroxanthandrus Kassebeer, 2000 in the Afrotropical region.

Figs 2–6. Frontal view of the head of species of Afroxanthandrus Kassebeer, 2000. 2. A. comorosensis sp. nov., holotype, ♂ (RMCA ENT 000056900). 3. A. congensis (Curran, 1938), ♂ (ANHRTUK 00282353). 4. A. conopeum sp. nov., holotype, ♂ (NMSA-Dip 219971). 5. A. congensis, ♀ (ANHRTUK 00282352). 6. A. longipilus Kassebeer, 2000, ♀ (ANHRTUK 00282356). Scale bars = 1 mm.

Figs 9–10. Lateral view of species of Afroxanthandrus Kassebeer, 2000. 9. A. conopeum sp. nov., holotype, ♂ (NMSA-Dip 219971). 10. A. congensis (Curran, 1938), ♀ (ANHRTUK 00282352). Scale bars = 1 mm.

Figs 13–17. Dorsal view of the abdomen of species of Afroxanthandrus Kassebeer, 2000. 13. A. comorosensis sp. nov., holotype, ♂ (RMCA ENT 000056900). 14. A. congensis (Curran, 1938), ♂ (ANHRTUK 00282353).15. A. conopeumsp. nov., holotype, ♂ (NMSA-Dip 219971). 16. A. congensis, ♀ (ANHRTUK 00282352). 17. A. longipilus Kassebeer, 2000, ♀ (ANHRTUK 00282356). Scale bars = 1 mm.

Figs 18–23. Male genitalia of species of Afroxanthandrus Kassebeer, 2000. 18–20. Dorsal views. 18. A. comorosensis sp. nov., holotype (RMCA ENT 000056900). 19. A. congensis (Curran, 1938) (RMCA ENT 000028396). 20. A. conopeum sp. nov., paratype (NMSA-Dip 086809). 21–23. Lateral views. 21. A. comorosensis sp. nov., holotype (RMCA ENT 000056900). 22. A. congensis (RMCA ENT 000028396). 23. A. conopeum sp. nov., paratype (NMSA-Dip 086809). Scale bars = 0.5 mm.

Fig. 24. Neighbour-Joining tree generated from DNA barcode data for four species of Afroxanthandrus Kassebeer, 2000.