Megaselia fuscilobulorum Disney, 2013

Disney, R. Henry L., Kurina, Olavi, Tedersoo, Leho & Cakpo, Yvonne, 2013, Scuttle flies (Diptera: Phoridae) reared from fungi in Benin, African Invertebrates 54 (2), pp. 357-357 : 362-363

Megaselia fuscilobulorum Disney , sp. n.

Figs 7–10

Etymology: From Latin fuscus (dark) and lobus (lobe), with reference to the female’s dark, sclerotised lobes at the rear of abdominal sternum 8.

Description:

Male.

Frons brown, clearly broader than long, with 60–90 hairs and dense but very fine microtrichia. SAs with lower pair shorter than longest bristles on palps. The antials lower on frons than ALs, and further from upper SAs as either is from AL. Pre-ocellars about as far apart as upper SAs, and as either is from ML, which is very slightly higher on frons. Cheek with 1 or 2 (usually 2) bristles and with two longer ones on jowl. Subglobose postpedicels pale dusky yellow without subcutaneous pit sensilla (SPS vesicles), but unusually with irregular basal rims surrounding the pedicels. Palps pale yellow, 1.6× as broad as labrum but slightly longer than breadth of postpedicel, with 5 or 6 bristles (longest being longer than lower SAs) and half as many hairs. Labrum pale yellow and about ⅔ as wide as postpedicel. Labella coloured as palps, each with 2 hairs above and with very few short spinules below. Thorax with orange to yellowish brown scutum, a darker scutellum and paler pleural regions apart from brown on pteropleura. Three notopleural bristles and no cleft in front of these. Mesopleuron bare. Scutellum with anterior pair of hairs (about equal to those in middle of scutum) and posterior pair of bristles.Abdominal tergites partly brown, and partly yellow. Typically T1 entirely brown, T2 and T6 yellow in their anterior halves at least, and T3 to T5 with variably yellow median patches in their anterior halves at least. Hairs tend to be most numerous towards hind margins and posterolaterally, and longest at T6 hind margin. Venter yellow, and with conspicuous hairs on segments 3–6. Hypopygium ( Fig. 10 ) brown, with yellow anal tube. Right lobe of hypandrium vestigial. Legs yellow apart from brown patches on mid coxae and tips of hind femora. Fore tarsus with pd hair palisade on segments 1–5, but that on 5 is abbreviated, and segment 5 about as long as 4. Dorsal hair palisade of mid tibia extends almost 0.75× of its length. Segment 4 of mid tarsus longer than segment 5. Hairs below basal half of hind femur longer than those of av row of outer half. Hind tibia with 3 or 4 differentiated hairs in basal region ( Fig. 7 ) and a dozen weakly differentiated pd setae apart from a stronger one just beyond mid point; spinules of apical combs simple. Wings 1.0– 1.3 mm long. Costal index 0.42–0.46. Costal ratios 4.0–5.0:2.4–3.6:1. Costal cilia (section 3) 0.06–07 mm long. No hair at base of vein 3. With 2 axillary bristles, outer being longer than costal cilia. Sc not reaching R1. Thick veins yellowish grey, thin veins 4–6 grey and 7 pale. Membrane lightly tinged grey (just evident to naked eye when viewed against a white background). Haltere knob yellow. Female.

Head similar to male but labrum about 1.1× as wide as a postpedicel and inner edges of labella with 5 teeth. Thorax as male. Abdominal T1–5 with anterior halves to two thirds yellow and the rest brown, but T6 largely yellow with a little brown at rear. Small hairs on all tergites but 1 or 2 longer ones towards sides of T2 and at rear of T6. T7 subrectangular, but very slightly tapered, and largely light brown; and about 1.5× as long as broad with a dozen hairs in its rear half and 4 longer ones at its hind margin. Venter yellowish grey, with conspicuous hairs below on segments 3–6. Sternite 7 brown, 1.6–1.7× as long as broad, tapering forwards in anterior half, with about 10 hairs and 4 longer setae at rear margin. Lobes at rear of sternum 8 brown to almost black and as Figs 8 & 9 . Cerci pale, 2.2–2.5× as long as greatest breadth, epiproct small. With 4 rectal papillae. Furca not evident. Dufour’s crop mechanism about 1.4× as long as greatest breadth and with a straight to slightly convex hind margin. Legs similar to male but hind tibia with about 10 differentiated pd hairs, last 3 being stronger than the rest. Wing as male except 1.2–1.5 mm long. Costal index as male. Costal ratios 3.7– 5.8:2.4–3.6:1. Costal cilia as male. Haltere as male.

Holotype: ♂ BENIN: Koussanzamou , ex Russula sp. 2 ( TU116098 ), 5.vii, emerged 15–18.vii ( UCMZ, 42-9).

Paratypes and other material examined: 1♀ (5♂ 38♀) same data as holotype (42-9); 2♂ same locality, ex Russula sp. 5 (TU116101), 5.vii, emerged 17–18.vii (42-9); 1♀ same locality, ex Boletaceae sp. (TU116120), 5.vii, emerged 15–20.vii (42-5); 1♂ 1♀ (2♂ 1♀) Kpessou, ex Lactarius flammans Verbeken (TU116003), 30.vi, emerged 14.vii (42-10); 1♂ (4♂ 6♀) same locality, ex Russula sp. (TU116010), 30.vi, emerged 12–19. vii (42-11); 1♀ same locality, ex Russula sp. (TU116010), 30.vi, emerged 12–19.vii (42-10); 1♂ 1♀ (3♂ 3♀) same locality, ex Russula oleifera Buyck (TU116042), 2.vii, emerged 13–14.vii (42-6); 1♂ 1♀ (1♂ 1♀) same locality, ex Russula sp. 1 (TU116043), 2.vii, emerged 13.vii (42-6); 1♂ 1♀ (17♂ 47♀) same locality, ex Russula sp. 2 (TU116044), 2.vii, emerged 13–20.vii (42-7); (1♂ 3♀) same locality, ex Boletaceae sp. (TU116047), 2.vii, emerged 10–13.vii (42-6); 1♂ 1♀ (12♂ 10♀) same locality, ex Russula sp. (TU116060), 4.vii, emerged 14–22.vii (42-6); (2♀) same locality, ex Russula sp. (TU116061), 4.vii, emerged 13.vii (42-6); 1♂ 1♀ same locality, ex Bovista sp. (TU116065), 4.vii, emerged 13.vii (42-11); 1♀ (2♂ 4♀) Ouari Maro, ex Lactarius gymnocarpoides Verbeken (TU116025), 1.vii, emerged 12–15.vii (42-10); 1♀ (1♀) same locality, ex Russula sp. 1 (TU116026), 1.vii, emerged 12–16.vii (42-7); (1♂ 7♀) same locality, ex Russula sp. 1 (TU116031), 1.vii, emerged 13–19.vii (42-7); 1♂ same locality, ex Russula sp. 2 (TU116 032), 1.vii, emerged 13–19.vii (42-7); (2♀) same locality, ex Russula sp. 4 (TU116034), 1.vii, emerged 12–15. vii (42-7); (3♀) same locality, ex Amanita pulverulenta Beeli (TU116037), 1.vii, emerged 12–15.vii (42-8). Remarks: In Beyer’s (1965) keys the male runs to page 54, couplet 28 to M. tergatula , only known from the female, but the latter has brown postpedicels. Proceeding the male runs to couplet 30, lead 2, to M. nubila , but the latter has brown legs. Some males with a costal index of less than 0.44 will run down on page 56 to couplet 4, but its haltere knob being yellow not brown one proceeds to couplet 5. Its thorax being paler not dark brown means one then proceeds to couplet 10, where the yellow legs and thorax exclude both species. The female on page 54 runs to couplet 22, to M. incrassaticosta , only known from the male, but its thorax is dark brown rather than pale brown at most. Proceeding to couplets 24 to 26 based on males only, one can continue on the basis of the costal index or costal cilia being too short for the species of these couplets. It then runs to couplet 30 to M. nubila again.

Figures

Figs 7–10. Megaselia fuscilobulorum sp. n., ♂ (7, 10) and ♀ (8, 9): (7) anterior face of base of hind tibia, (8, 9) lobes at rear of sternum 8 in two different specimens, (10) left face of hypopygium. Scale bar= 0.1 mm.