Megaselia polonici Disney & Durska 2020, sp. nov.

Megaselia polonici Disney, sp. nov.

(Figs 33–43)

Description. (Male). In the key to the males of the species of Megaselia recorded from the British Isles

(Disney 1989), it runs to couplet 126 lead 2 M. unguicularis (Wood) but its hypopygium is different. Of 15 additions running to the same couplet only M. geiri Disney is close but its hypopygium has fewer long bristles and instead of hairs below the basal half of the hind femur it has short bristles. In Schmitz’s (1958) key to Abteilung IV Erste Reihe it runs to couplet 9 lead 2 M. lapponica Schmitz, but it has the costal index exceeding 0.48, subequal supra-antennal bristles and a different hypopygium. In Schmitz & Beyer’s (1965 b) key to Abteilung IV Zweite Reihe it runs to couplets 95–97, but its hypopygium fits none of the options (with most already excluded in the key to the males of the British Isles). In Borgmeier’s (1964) key to Nearctic species for Group IV it runs either to couplet 18 lead 1 M. perichaeta Borgmeier, whose hypopygium is similar but its venter is dark and it has 4 axillary bristles; or else it runs to couplet 31 lead 2 M. cirripyga Borgmeir, but its hypopygium is different. In his key to Group V it fails to key out due to its distinctive hypopygium. Note, the middle legs are missing in the only specimen available.

Male. Head as Fig. 33. Frons as Fig. 34, with dense but very fine microtrichia. Cheek with 3 bristles and jowl with 2 that are longer and more robust. Postpedicels, which lackt SPS vesicles, palps and proboscis as Fig. 35, the labella with very few short spinules below. Thorax and abdomen as Figs 36 and 37, with 3 notopleural bristles and no cleft in front of these, and mesopleuron with 3 small hairs, and scutellum with an anterior pair of small hairs and a posterior pair of bristles. Abdomen, with pale venter with hairs on segments 3–6, as Fig. 37. Hypopygium as Figs 38–40. Hind legs with brown femur and tibia. Front femora yellowish

brown. Fore tarsus with posterodorsal hair palisades on segments 1–4 and 5 just longer than 4 (Fig. 41). Hairs below basal half of hind femur about as long as those of anteroventral row of outer half (Fig. 42). Hind tibia with a dozen moderately differentiated posterodorsal hairs, without anterodorsals, and spinules of apical combs simple. Wings (Fig. 43) 1.33 mm long. Costal index 0.44. Costal ratios 3.43: 1.57: 1. Costal cilia (of section 3) 0.10 mm long. No vein 3 hair. 2 unequal axillary bristles, the outermost being 0.09 mm long. Sc not reaching R1. Haltere knob brown (Fig. 23).

Type material. Holotype male, Poland, Wigry National Park, in emergence trap in plot 4BA without Impatients parviflora DC, IX. 2018, E. Durska leg. (MIZ PAS, – 28-62).

Etymology. Named after the hundredth anniversary of Poland’s (polonici) independence – on November 11, 2018.