Phaonia subventa (Harris)

Michelsen, Verner & Pont, Adrian C., 2024, Macaronesian Muscidae (Diptera). V. The genera Phaonia Robineau-Desvoidy and Muscina Robineau-Desvoidy, Zootaxa 5458 (4), pp. 581-596 : 590-592

6. Phaonia subventa (Harris)

( Fig. 5 )

Phaonia variegata (Meigen) ; Séguy 1936: 24 (Azores).

Phaonia testacea (Fabricius) (= P. variegata (Meigen)) ; Frey 1945: 106 (Azores); Ringdahl 1960: 98 (Azores).

“ Phaonia testacea ”; Kehlmaier 1998: 85 (Azores).

“ Phaonia rufiventris (Scopoli) ”; Pont & Báez 2006 (Azores); Pont 2010: 237 (Azores). Misidentifications.

Taxonomic note. Phaonia rufiventris , a common species in temperate and boreal Europe, has erroneously been included in recent lists of Diptera from the Azores. The background for this mistake is a longstanding ambiguity regarding the identity of Musca testacea Fabricius. Stein (1907) listed it as a questionable synonym of the common and widespread Phaonia variegata (Meigen) [now = P. subventa (Harris) ], a species known from the Azores since Séguy (1936). Frey (1945), followed by Ringdahl (1960), ignored P. Stein’s reservation concerning the identity of Musca testacea and recorded it from the Azores as “ Phaonia testacea (Fabricius) (= P. variegata (Meigen) ”. Michelsen (1979), in the absence of type material, was unable to clarify the identity of Musca testacea Fabricius , but hinted at Phaonia populi (Meigen) [now = P. rufiventris (Scopoli) ] as a possible synonym, an identity accepted and confirmed by Pont (1986). The name “ Phaonia testacea ” appears in the first checklist of Azorean Diptera by Kehlmaier (1998), obviously taken from Frey (1945), and thus refers to Phaonia subventa . The presence of Phaonia rufiventris along with P. subventa in subsequent Azorean checklists ( Pont & Báez 2002; Pont 2010) is an error caused by interpreting Kehlmaier’s “ Phaonia testacea ” in the sense of Pont (1986).

Material examined. AZORES: [ BMNH, MZH] São Jorge , cathedral roof, 3♂ 2.v.1903 (W.R.O Grant); São Miguel, Furnas , 1♂ 23.vii–1.viii.1938 (R. Frey) . MADEIRA: [ MZH, NHMD] Boa Morte–Quinta Grande, 550m, 1♀ 21.iv.1995 (M. Koponen); Faja da Nogueira , 800m, moist laurisilva, 2♀ 25.xi.2001 (V. Michelsen) .

Description. Medium to large sized, wing length 6.5–8.2 mm. Male: Antenna brownish to black; palp yellow; thorax with four broad black stripes well visible on greyish pruinose mesonotum; scutellum yellow on distal two-thirds or more; anterior spiracle with yellow fringes, those on posterior spiracle ochre yellow; calypteres and halter pale yellowish; cross-veins r-m and m-cu narrowly shadowed; legs yellow except for dark brown tarsi; abdomen yellow, sometimes with a narrow dark mid-dorsal stripe that may expand into trapezoid dark marks on tergites III and IV. Eyes with dense pile. Arista short-plumose, longest aristal branches two-thirds as long as width of postpedicel; frons at narrowest point usually narrower than anterior ocellus with frontal vitta suppressed by contiguous fronto-orbital plates. Dorsocentral setae 2 + 4; acrostichal setae 2–3 + 2–3 (including prescutellar seta); notopleuron without setulae; prealar seta about same length as posterior notopleural seta; katepisternal setae 1 + 2; katepimeron bare; meron with 0–5 setulae beneath posterior spiracle; vein C practically bare dorsally. Fore tibia with 0–1 p seta; mid tibia with 0 ad and 2 p setae; hind femur with complete row of av setae and pv setae confined to basal half; hind tibia with 2–3 av and 2 ad setae. Female: Apart from usual sexual differences of the head and abdomen, differing from the male by much shorter pile on eyes, hind femur with av setae confined to distal half, and with fewer basal pv setae.

Distribution. A common and widespread W Palaearctic species known from the Azores and Madeira (new record!). A recent find at the east coast of the United States ( Vikhrev & Erofeeva 2018; N.E. Vikhrev comm.) represents an accidental introduction to the Nearctic region.

Figures

FIGURE 5. Muscina prolapsa prolapsa (Harris), (A, C), M. prolapsa fuscisquama ssp. nov., (B, D). (A, B), habitus, male; (C, D), abdomen, male.