Megaselia kajnisseni Henry & Bøggild 2021, sp. n.

Megaselia kajnisseni sp. n. (Figs 121–131) Diagnosis. In the key of Lundbeck (1922) it runs to Group VII couplet 6 lead 1 to M. lactipennis (Lundbeck), but it lacks SPS vesicles in its postpedicels, has much shorter hairs at the rear of tergite 6 and has a bristle in addition to hairs on the epandrium. In the key to the males of the British species (Disney, 1989) it runs to couplet 288, where neither lead applies. One omitted species has a much longer costal index and at least 6 axillary bristles. The subsequently described M. lacockensis Disney and M. madeiraensis Disney are both very similar. In the former the hairs at rear of T6 (0.07 mm) are at least twice as long as longest hairs on the epandrium (0.03 mm). In M. madeiraensis the hairs at the rear of T6 are exceptionally short at 0.02 mm and the hairs of the epandrium are at most twice as long and the hairs at the tip of the proctiger that are about 0.06 mm long. It fails to run down in keys for the rest of the world’s fauna and subsequent additions. Description. Male. Head as Fig. 121, with dense but very fine microtrichia. Cheek with 3 bristles and jowl with 2 that are longer and more robust. Postpedicels (Fig. 122), with SPS vesicles. Palps yellowish (Fig. 121). Thorax brown, with 3 notopleural bristles and no cleft in front of these, and mesopleuron bare (Fig. 123). Scutellum with an anterior pair of hairs and a posterior pair of bristles. Abdominal tergites brown with relatively small hairs (Fig. 124), those at the rear of T6 being only 0.06 mm long. Venter gray, and with numerous hairs on segments 3–6 (Fig. 124). Hypopygium as Figs 125–127, the hairs of the epandrium being up to 0.08 mm long and those a tip of protiger being 0.07–0.08 mm long. Hypandrium with left lobe as Fig. 126, but right lobe vestigial (Fig. 127). Legs with brown but not dark hind femora and the rest progressively more yellowish. Fore tarsus (Fig. 128) with posterodorsal hair palisade on segments 1–4 and 5 longer than 4 but a little wider (Fig. 129). Dorsal hair palisade of mid tibia extends about 0.52 times its length. Hairs below basal half of hind femur shorter than those of anteroventral row of outer half (Fig. 130). Hind tibia with about two dozen only differentiated posterodorsal hairs, without anterodorsals, and spinules of apical combs simple. Wings (131) pale, especially the thin veins, and about 1.52 mm long mm long. Costal index about 0.37. Costal ratios 3.43: 1.52: 1. Costal cilia (of section 3) 0.07 mm long mm long. Vein 3 hair probably lacking. With 2 unequal axillary bristles, the outermost being 0.10 mm long mm long. Sc fading as it reaches R1. Haltere knob brown. Type material. Holotype male, DENMARK, DK NEJ, Høstemark Skov, 21.VI.–14.VII. 2007, Esben Bøggild (UCMZ —9–26). Etymology. Named after Kaj Nissen, naturalist and conservationist and Esben’s neighbour.Published as part of Henry, R. & Bøggild, Esben, 2021, Nineteen new species of Megaselia Rondani (Diptera, Phoridae) from Denmark, pp. 306-342 in Zootaxa 4975 (2) on pages 321-324, DOI: 10.11646/zootaxa.4975.2.4, http://zenodo.org/record/492521