Megaselia neuter, Henry & Bøggild, 2021

Henry, R. & Bøggild, Esben, 2021, Nineteen new species of Megaselia Rondani (Diptera, Phoridae) from Denmark, Zootaxa 4975 (2), pp. 306-342 : 326-328

Megaselia neuter n. sp.

(Figs 157–168)

Diagnosis. In the key of Lundbeck (1922) for Group IV it runs to couplet 33 M. barbulata (Wood), but it has a very different hypopygium ( Fig. 2 in Disney, 1991). In the key to the males of the British species ( Disney, 1989) it runs to couplet 102, but its hypopygium differs from both species. In the keys of Schmitz & Beyer (1965) for Abteilung IV Zweite Reihe it runs couplet 71. However, the supposed difference in the number of costal cilia between the two options is negated by reference to their photo of the wing for M. raetica Schmitz. The latter has a clearly different hypopygium from the two species encountered by proceeding to couplet 72. Our species has a hypopygium similar but different from those of M. fusciclava Schmitz and M. fuscipalpis (Lundbeck) . The latter is immediately distinguished by its legs being entirely dark brown. M. fusciclava differs from our species in having a posterodorsal hair palisade on all 5 segments of the front tarsus and its costal index exceeding 0.48. In Bormeier’s (1964) key for Nearctic Group IV species it runs to couplet 17 lead 1 M. difficilis (Malloch), but its wing has 6 axillary bristles and clearly longer costal cilia at 0.16–0.18 mm. It fails to run down in keys for the rest of the world’s fauna and subsequent additions.

Description. Male. Frons as Fig. 157, and lacking fine microtrichia except at front (Fig. 158). Cheek with 3 bristles and jowl with 2 that are longer and more robust. Postpedicels, with a few SPS vesicles, palps and proboscis as Fig. 159. The labella with some but not very many short spinules below (Fig. 160). Thorax brown, with 3 notopleural bristles, with no cleft in front of these, and mesopleuron with hairs (Fig. 161). Scutellum with an anterior pair of small hairs and a posterior pair of bristles. Abdominal tergites and venter as Fig. 162, the latter with hairs on segments 3–6. Hypopygium as Figs 163–165. Legs yellowish but the hind femora yellowish brown. Fore tarsus with posterodorsal hair palisades on segments 1 to 4 (Fig. 166). Mid tibia with dorsal hair palisade about 0.63 times its length. Hairs below basal half of hind femur marginally shorter than those of anteroventral row of outer half (Fig. 167). Hind tibia with about a dozen moderately differentiated posterodorsal hairs, without anterodorsals, and spinules of apical combs simple. Wings (Fig. 168) 1.4 mm long. Costal index 0.46. Costal ratios 3.4–3.5: 1.6–1.7: 1. Costal cilia (of section 3) 0.15 mm long. Vein 3 hair 0.1 mm long. 3 axillary bristles, the outermost being 0.10 mm long. Sc not reaching R1. Haltere knob pale (Fig. 162).

Type material. Holotype male, DENMARK, DK, EJ, Onsild Mose , 21.V.–5.VI.2017, Esben Bøggild ( UCMZ — 9–18).

Etymology. Named after it being neither one nor the other ( neuter ) with its hypopygium being intermediate between M. fusciclava Schmitz and M. fuscipalpis (Lundbeck) .

Figures

FIGURES 1–11. Megaselia culmenensis n. sp. male. 1, frons; 2, antennae, palps and proboscis; 3, postpedicel; 4, side of thorax; 5, dorsal view of abdominal tergites 2–6; 6; left face of hypopygioum; 7–8, right faces of hypopygium; 9, front tarsus; 10, hind femur; 11, wing.