Megaselia falloclavis, Henry & Bøggild, 2021

Henry, R. & Bøggild, Esben, 2021, Nineteen new species of Megaselia Rondani (Diptera, Phoridae) from Denmark, Zootaxa 4975 (2), pp. 306-342 : 313-316

Megaselia falloclavis n. sp.,

( Figs 61–72 )

Diagnosis. In the keys of Lundbeck (1922) it runs to Group VI couplet 17 lead 1 M. minor (Zetterstedt). However, this was a misidentification of M. minuta (Aldrich) ( Disney, 1984) , which is immediately distinguished from our species by its notopleuron having only 2 bristles and a notopleural cleft. With the costal index being 0.44 one needs to check whether it keys out in Group VII, where it runs to couplet 15, where neither option fits. In the key to the males of the British species ( Disney, 1989) it runs to couplet 232 where one is returned to couplet 194 and thence to couplet 226, where one is returned to couplet 232! Of the additional species running to this couplet 4 have clearly different hypopygia along with brown hind femora and/or postpedicels with SPS vesicles and/or a costal index exceeding 0.5. A further 2 are considered below. In Borgmeier’s (1966) key to Nearctic species of Group VII it runs to couplet 12, where neither option fits. In his key to Group VIII it runs to couplet 10 lead 1 M. bovista (Gimmerthal). However, Borgmeier misidentified M. agarici (Lintner) as this species, and prior to the description of the male of M. abdita Schmitz (under its synonym M. griseipennis Santos Abreu ) ( Disney, 1987, ICZN, 2012), these two species were being confused. Furthermore, the similar Nearctic M. agarici and Arabian and Oriental M. sandhui Disney had also been confused ( Disney, 2008). The male of M. sandhui has a curious ‘pocket’ on its abdominal venter. M. abdita has brown hind femora whose basal hairs are shorter than the anteroventral hairs and a different hypopygium with a shorter anal tube. Our species fails to run down in keys for the rest of the world’s fauna and subsequent additions.

Description. Male. Frons as Fig. 61 , with microtrichia absent except at extreme margins, but with more than 80 hairs. The upper supra-antennal bristles are further apart than the pre-ocellars. Cheek with 3 bristles and jowl with 2 that are longer and more robust. Postpedicels, without SPS vesicles, palps and proboscis as Fig. 62 , the labella with only a few short spinules below. Thorax brown. With 3 notopleural bristles and no cleft in front of these ( Fig. 63 ). Mesopleuron bare. Scutellum with an anterior pair of hairs and a posterior pair of bristles ( Fig. 64 ).Abdomen as Fig. 65 , the venter with hairs on segments 3–6. Hypopygium as Figs 66–69 . Legs yellowish. Fore tarsus ( Fig. 70 ) with posterodorsal hair palisade on segments 1–4. Dorsal hair palisade of mid tibia extends about 0.66 times its length. Hairs below basal half of hind femur ( Fig. 71 ) same length as those of anteroventral row of outer half. Hind tibia with about a dozen differentiated posterodorsal hairs, without anterodorsals, and spinules of apical combs simple. Wings ( Fig. 72 ) 1.36 mm long. Costal index 0.44. Costal ratios 3.95: 1.4: 1. Costal cilia (of section 3) 0.08 mm long. Vein 3 hair 0.02 mm long. 4 axillary bristles, the outermost being 0.11 mm long. Sc not reaching R1. Haltere knob pale ( Fig. 64 ).

Type material Holotype male, DENMARK, DK SJ, Draved Skov , 12–30.VII.2014, Esben Bøggild ( UCMZ — 9–20).

Etymology. Named after fallo (fail) clavis (key) with reference to its failure to key out in the relevant keys.

Figures

FIGURES 61–72. Megaselia falloclavisi sp. n. male. 61, frons; 62, postpedicels to proboscis; 63, notopleuron; 64, scutellum and Haltere; 65, abdomen; 66, left face of hypopygium; 67, left face of epandrium; 68, left face of hypandrium; 69, right face of hypopygium; 70, front tarsus; 71, hind femur; 72, base of wing.