Megaselia onsildensis n. sp.

(Figs 173–182, 239–240)

Diagnosis. In the key of Lundbeck (1922) for Group VII it runs to couplet 22 lead 1 M. maura (Wood), but it has a different hypopygium with well developed hypandrial lobes. In the key to the males of the British species (Disney, 1989) it runs to couplet 263 lead 2 top M. maura or couplet 225 lead 1 M. sptemtrionalis (Schmitz). However, the latter having been described from the female only, recognition of this species gave rise to confusion prior to augmentation of its description by Buck & Disney (2001) and the male previously attributed to this species being recognized as the new species M. labellaspinata Disney. It has a different hypopygium, a costal index exceeding 0.45, posterodorsal hair palisades on all five joints of the front tarsus and postpedicels with SPS vesicles. Subsequently 5 added species running to these couplets, apart from their different hypopygia, differ in one or more of the following featuresposterodorsal hair palisades on all five segments of the front tarsus, postpedicels with SPS vesicles, 3 notopleural bristles, costal index exceeding 0.43. In Borgmeier’s (1966) key to Nearctic Group VIII it runs to couplet 15 lead 2 M. pygmaeola Borgmeier, which has very short microsetae on its antennal aristae and very weak posterodorsal hairs on the hind tibiae. Our species fails to run down in keys for the rest of the world’s fauna and subsequent additions.

Description. Male. Frons as Fig. 173, with dense but very fine microtrichia all over and upper supra-antennal bristles further apart than the pre-ocellars. Cheek with 4 bristles and jowl with 2 that are longer and more robust. Antennae, palps, proboscis as Fig. 174, the labella having short spinules below (Fig. 175). Thorax brown, with 2 notopleural bristles and no cleft in front of these, and mesopleuron bare (Fig. 176). Scutellum with an anterior pair of small hairs and a posterior pair of bristles. Abdominal tergites and venter as Fig 177, the venter having small hairs on segments 3–6. Hypopygium as Figs 178, 179, 239 & 240. The hypandrial lobes being vestigial. Legs yellowish brown to pale yellow. Fore tarsus (Fig. 180) with posterodorsal hair palisades on segments 1–4 and 5 longer than 4 and 5 a little darker. Dorsal hair palisade of mid tibia extends about 75 times its length. Hairs below basal half of hind femur longer than those of anteroventral row of outer half (Fig. 181). Hind tibia with a dozen well differentiated posterodorsal hairs, without anterodorsals, and spinules of apical combs simple. Wings (fig. 241) with membrane only lightly tinged, thick veins light brown and thin veins pale gray. Wing length 1.9–2.1 mm. Costal index 0.38. Costal ratios 4.8–5.5: 1.2–1.5: 1. Costal cilia (of section 3) 0.10–0.11 mm long. Vein 3 hair 0.06 mm long. 4 axillary bristles, the outermost being 0.12–0.14 mm long. Sc not reaching R1. Haltere knob brown (Fig. 182).

Type material. Holotype male, DENMARK, DK EJ, Nr. Onsild Mose, 7–24.VII.2017, Esben Bøggild (UCMZ —9–23) . Paratype, DK EJ, Nr. Onsild Mose, 7–24.VII.2017, Esben Bøggild in ZMUC, Copenhagen. Also known from two sites in Sweden (Hartop & Bøggild, unpublished).

Etymology. Named after the type locality.