Phaonia gayaneae, Pont, 2018

Pont, Adrian C., 2018, The Muscidae (Diptera) of Armenia, Zootaxa 4465 (1), pp. 1-69 : 67-69

Phaonia gayaneae sp. nov.

( Figs 20–21 )

Diagnosis. Among the species of Phaonia Robineau-Desvoidy in which the male frons is very narrow and devoid of setae and setulae on upper half, P. gayaneae can be recognised by the long, strong prealar seta, 3 pairs of postsutural dorsocentrals, black palpus, yellow femora, and fore tibia without a posterior seta.

Etymology. This species is named for Gayane Aghajanyan of Dilijan, Armenia.

Type-material Examined. Holotype ♂. ARMENIA: Tavush province, Haghartsin monastery environs, N40.48 E44.53, 1440–1560 m, 23.vii.2015, A.C. Pont ( BMNH).

Description. ♂ ( Figs 20–21 )

Head. Holoptic. Ground-colour black. Eye virtually bare, with a few tiny scattered hairs. Fronto-orbital plate, parafacial, face and gena silvery-white pruinose, occiput grey. Frons very narrow ( Fig. 21 ), at narrowest point separated by a distance equal to width of anterior ocellus, and frontal vitta obliterated except on lower third of frons. Ocellar seta strong. 3–4 pairs of frontal setae with a few fine interstitials, confined to lower third of frons. Antenna black; postpedicel 2.5 times as long as broad. Arista long-plumose, the longest individual plumes as long as width of postpedicel. Parafacial narrow throughout, at level of aristal insertion half width of postpedicel. In lateral view, facial edge behind level of profrons. Gena moderate, depth below lowest eye-margin equal to a little more than width of postpedicel. Palpus black, slender. Mentum of proboscis dusted.

Thorax. Ground-colour black. Scutum densely grey dusted, with dark markings as follows: a pair of narrow paramedian vittae between the acrostichal and dorsocentral rows, running from neck to level of 3rd postsutural dorsocentral, before suture each vitta only one-third as wide as the grey dusted vitta separating them; a patch around presutural intraalar and supraalar; and postsuturally a vitta between dorsocentrals and intraalars. Pleura more thinly grey dusted. Acrostichals 0+1, presutural setulae in 5–6 irregular rows, dorsocentrals 2+3, intraalars 1+2, supraalars 1+2; 2 postpronotals; prealar long and strong, subequal to 2nd notopleural and both subequal to anterior notopleural. Anterior and posterior spiracles brown. Prosternum bare, notopleuron without setulae, proepisternal depression bare. Katepisternals 1+2, the lower one much closer to posterior upper than to anterior upper seta. Meron and katepimeron bare. Scutellum dusted as scutum, with 1 strong preapical and 1 strong basal lateral setae; lateral margins and ventral surface bare.

Legs. Coxae and trochanters mostly dark; fore femur yellow but with some infuscation on apical half of anterior surface, otherwise femora and tibiae yellow; tarsi black. Fore femur with rows of posterodorsal and strong dense posteroventral setae. Fore tibia without a submedian posterior seta, with strong apical dorsal and anterodorsal setae, without a posteroventral apical. Fore tarsomere 1 with a short ventral seta at base. Mid femur with long anteroventral setulae but no setae, with 5–6 posteroventral setae in basal half which continue as more erect posteroventral setulae in apical half; 2 anterior to anterodorsal and 3 dorsal to posterior preapical setae. Mid tibia with 3 posterior setae, without anterodorsals or posteroventrals. Hind femur with a complete anterodorsal row; posteroventral surface without setae; anteroventral surface with a row of setae, shorter and weaker in basal half. Hind tibia with calcar strong; 2 anterodorsals, and 3 anteroventrals; dorsal and anterodorsal preapicals strong; 1 anteroventral but no posteroventral apical seta.

Wing. Yellowish, more strongly so at base. Basicosta and tegula black. Vein M straight, diverging slightly from vein R4+5 towards wing-tip. Crossvein r-m slightly basad of the point where subcosta enters costa, and crossvein dm-cu oblique, weakly curved. Costal spine short. Stem-vein and vein R4+5 bare. Calypters yellowish, margins yellow. Haltere wholly yellow.

Abdomen. Elongate, narrow. Ground-colour black. Tergites densely grey dusted, tinged with yellow, with black markings as follows: syntergite 1+2 with a median vitta; tergites 3, 4 and 5 each with a black median vitta which expands posteriorly and joins a narrow black hind-marginal band on each tergite, less extensive on tergite 3 but covering most of dorsal surface of tergite 5. Tergite 3 with some lateral marginals; tergite 4 with lateral discals and a marginal row; tergiute 5 with complete rows of discal and marginal setae. Sternite 1 bare.

Measurements. Length of body, 7.0 mm. Length of wing 6.0 mm.

Relationships. In Hennig’s (1963) key to Palaearctic Phaonia , P. gayaneae will run to couplet 188 as it has 3 pairs of postsutural dorsocentrals, but the fore tibia has no submedian seta. All the femora are yellow, as in P. profugax (Pandellé) which P. gayaneae appears to resemble most closely. Hennig (1963: 858–860) discussed in some detail what he considered to be two seasonal generations of this species and their differences. P. gayaneae differs from P. profugax in a number of respects: longest aristal plumes as long as width of postpedicel; fronto-orbital plates contiguous and each one narrower than width of anterior ocellus; prealar and the two notopleural setae subequal in length, and notopleuron without a setula; fore femur yellow; fore tibia without a submedian seta; mid femur with a row of posteroventral setae in basal half; hind tibia with 2 anterodorsal setae.

Figures

FIGURES 20–21. Phaonia gayaneae sp. nov. 20. Male, lateral view (holotype). 21. Male head, frontal view (holotype).