Megaselia exwignatpark Disney, 2020

Disney, R. Henry L. & Durska, Ewa, 2020, New Species And New Records Of Megaselia Rondani (Insecta: Diptera: Phoridae) From Wigry National Park (Poland), Annales Zoologici 70 (1), pp. 97-108 : 98

Megaselia exwignatpark Disney , sp. nov.

( Figs 10–20 )

Description. (Male). The specimen is anomalous in that its scutellum has a pair of bristles on its right side but an anterior bristle and a posterior hair on its left side. The right side is assumed to be its normal state due the hair on the left side being behind its bristle. In the key to the males of the species of Megaselia recorded from the British Isles ( Disney 1989) it runs to couplet 30 lead 1 M. paludosa (Wood) but its hypopygium is clearly different. The excluded M. fennicola (Beyer) runs to this point but its hypopygium and spinose labella eliminate this species. In Schmitz’s (1956) key to Abteilung I it runs to M. paludosa already eliminated in the key to British species. In Borgmeir’s (1964) key to Nearctic Group I it runs to couplet 6 where the relative lengths of the scutellar bristles cannot be determined as only their sockets are present. Taking the first option it keys to M. relicta Borgmeier but its wings and frontal bristle arrangements differ. Proceeding to couplet 7 it runs to lead 2 M. wirthi Borgmeier, a synonym of M. plebia (Malloch) , but likewise its wings and frontal bristle arrangements differ. It fails to key lout in the rest of world’s fauna.

Male. Frons as Fig. 10 , with dense but very fine microtrichia. Cheek with 4 bristles and jowl with 2 that are longer and more robust. Postpedicels, without SPS vesicles but with many spots, and palps as Fig. 11 . Proboscis as Fig. 12 , the labella lacking short spinules below. Thorax with 3 notopleural bristles and no cleft in front of these, as Fig. 13 . The specimen is anomalous in that its scutellum has a pair of bristles on its right side but an anterior bristle and a posterior hair on its left side ( Fig. 14 ). The right side is assumed to be its normal state due the hair on the left side being behind its bristle. Abdomen as Fig. 15 , the venter seemingly with hairs on segments 5 and 6 only. Hypopygium as Figs 16–17 , the hypandrial lobes being vestigial Legs yellowish. Fore tarsus with posterodorsal hair palisade on segments 1–5 and 5 clearly longer than 4 (note only one front leg is present and its segments 5 and 6 are detached from the rest) ( Figs 18 & 19 ). Dorsal hair palisade of mid tibia extends about 0.6 times its length. Hairs below basal half of hind femur longer than those of anteroventral row of outer half ( Fig. 20 ). Hind tibia with 15–16 only a little differentiated posterodorsal hairs, without anterodorsals, and spinules of apical combs simple. Both wings are incomplete with costal section 2 incomplete on what remains of both wings, hence the relevant measurements are best estimates. 1.5–1.6 mm long. Costal index about 0.50. Costal ratios 3.47:1.2–1.3: 1. Costal cilia (of section 3) 0.08 mm long. No vein on 3 hair. 2 axillary bristles, the outermost being 0.08 mm long. Sc not reaching R1. Haltere knob brown.

Type material. Holotype male, Poland, Wigry National Park , in emergence trap in plot 5 with Impatients parviflora DC, IX. 2017, E. Durska leg. ( MIZ PAS, – 28-59).

Etymology. Named after Wigry National Park.

Figures

Figures 10–20. Megaselia exwignatpark Disney, sp. nov. male. 10 – frons; 11 – postpedicels, palps and proboscis; 12 – postpedicel; 13 – side of thorax; 14 – left half of scitellum; 15 – abdomen; 16, 17 – left and right views of hypopygium; 18, 19 – front tarsus; 20 – hind femur.