Megaselia strynensis, DISNEY, 2020

DISNEY, R. Henry L., 2020, Scuttle flies (Diptera: Phoridae) from the canopies of ash trees in Norway, with six new species, Fragmenta Faunistica 63 (1), pp. 29-45 : 38-39

Megaselia strynensis n. sp.

( Figs 45–56 )

Diagnosis (male). In the key to the males of Megaselia from the British Isles ( Disney 1989) it runs to couplet 167 where either lead applies as the feathering of the epandrial bristles is only discerned at high magnifications. Lead 1 takes one to couplet 173, where neither option fits. Lead 2 proceeds to couplet 176 lead 2, but the hypopygium differs. Taking lead 2 from couplet 167 one proceeds to couplet 232 lead 2 which returns one to couplet 171 and one may also return to couplet 192. The closest of these options is M. sheppardi Disney (at couplet 172), but apart from its hypopygium it has a dark brown thorax and abdominal tergites. From couplet 192 one returns to couplet 171. Additional species running to these points differ by their hypopygia apart from dark thorax and abdominal tergites. With the Nearctic species one needs to try Borgmeir’s (1966) Group VII and Group VIII as the CI of 0.43 is too close to the division <0.44 or>0.44. With Group VII one runs to couplet 2, where the hypopygium doesn’t fit; and with Group VIII one runs to couplet 4, lead 1 M. decussata Borgmeir, but it has a yellow venter and a different brown hypopygium. It fails to key out for the rest of the world.

Male. Frons as Fig. 45 with dense but very fine microtrichia. Cheek with 2 bristles and jowl with 2 unequal bristles one of which is longer and more robust. Postpedicels, without SPS vesicles, palps and proboscis as Fig. 46 . Thorax orange to yellow. 3 notopleural bristles with no cleft in front of these and mesopleuron bare ( Fig. 47 ). Scutellum with an anterior pair of small hairs and a posterior of bristles ( Fig. 48 ). Abdomen as Fig. 49 , the venter with hairs on segments 3–6). Hypopygium as Figs 50–52 ) the epandrium having hairs and a pair of bristles each side. Left face of the hypandrium and penis complex as Fig. 51 , the right lobe being vestigial. Right face of hypopygium as Fig. 53 . All the Legs yellowish. Fore tarsus ( Fig. 54 ) with posterodorsal hair palisades on segments 1–4 and 5 clearly longer than 4. Dorsal hair palisade of mid tibia extends about 0.59 times its length. Hairs below basal half of hind femur longer than those of anteroventral row of outer half ( Fig. 55 ). Hind tibia ( Fig. 55 ) with 14–15 weakly differentiated posterodorsal hairs, without anterodorsals, and spinules of apical combs simple. Wings ( Fig. 56 long. Vein 3 hair 0.01 mm long. 3 axillary bristles, the outermost being 0.10 mm long. Sc not reaching R1. Haltere as Fig. 48 .

Material. Holotype male, Norway, Sogn & Fjord: Stryn , 61.8605º N, 6.3404º E, 15 Jul 2018, J. Svetlik & L. Børjia (11, UCMZ, 39–92–93).

Etymology. Named after the type locality.

Figures

Figs 45–50. Megaselia strynensis n. sp. male. 45 – frons; 46 – postpedicels, palps and proboscis; 47 – mesopleuron and notopleuron; 48 – scutellum and haltere; 49 – left face of abdomen; 50 – left face of hypopygium.

Figs 51-56. Megaselia strynensis n. sp. male. 51 - left face of lower half of epandrium; 52 - left face of hypandrium and penis complex; 53 - right face of hypopygium; 54 - front tarsus; 55 - hind femur and tibia; 56 - wing.