Hebecnema anthracina Stein

Michelsen, Verner, 2019, Macaronesian Muscidae (Diptera). I. The genus Hebecnema Schnabl with description of a new Canarian endemic species and a review of the European fauna, Zootaxa 4706 (2), pp. 332-348 : 333-335

Hebecnema anthracina Stein

( Figs 1 A‒D)

Hebecnema vespertina var. anthracina Stein ; Becker 1908b: 194 (Madeira).

Hebecnema anthracina Stein ; Hennig 1956: 140, text fig. 42, plate fig. 118 (Madeira).

Stein in Becker (1908b) proposed the name anthracina as a Madeiran variety of Hebecnema vespertina (Fallén) differing from the nominal form by the strikingly dark colour of the body, calypteres and wings. Hennig (1956) found also differences in the male terminalia and treated H. anthracina as a separate species endemic to Madeira, but closely related to the European H. affinis Malloch (now = H. vespertina ). The present study suggests, however, that the closest relative of H. anthracina is a species endemic to the western Canary Islands and described below as H. anthracinella sp. nov. Both species have darkly clouded calypteres and in this respect differ from other European species of Hebecnema ; they share a dark colour of the halter with H. nigra . Hebecnema anthracina and H. anthracinella sp. nov. differ substantially in the structure of the male terminalia, but the females appear morphologically inseparable and may presently only be identified on basis of their provenance.

Material examined. MADEIRA: Type material [ MNB]: Funchal, 2♂ syntypes iv.1904 (T. Becker). A female syntype in poor condition (head and some legs missing) with the same data is misassociated as it belongs to Hebecnema fumosa (Meigen) . Other material [ MZH, NHMD]. Valle de Paraiso, 5♂, 1♀ 18.iv.1959 (S. Panelius); Queimadas, 1♂ 24‒26.vi.1957 (H. Lindberg); 1♂, 1♀ 14‒16.v. 1959 (S. Panelius); Roseiros, 1♂ 17.iv.1990 (A. Koponen); Funchal, Preces‒Faja, 300m, 1♂ 11.xii.1994 (A. Koponen); Faja da Nogueira , moist laurisilva, 800m, 1♀ 25.xi.2001 (V. Michelsen) .

Diagnosis. Parafacials dull brownish grey in anterodorsal view. Thorax and abdomen with dark shine through thin brownish pruinosity; male abdomen with a narrow median dark stripe on tergites III‒V; female abdomen with uniform dark shine. Wing, calypteres and halter blackish clouded. Legs black with mid and hind tibiae darkly ochre yellow. Eye practically bare. Male head in profile with middle part of parafacial concealed behind the eye. Distance between presutural rows of acrostichal setae equal to (male) or slightly exceeding (female) their distance to rows of dorsocentral setae; setulae between acrostichal rows in two irregular rows. Vein C bare on dorsal surface. Hind tibia with 1‒2 av setae. Male sternite V, surstylus and cerci distinctive ( Figs 1 A‒D); the unique shape of sternite 5 is visible without dissection. Ovipositor of the Hebecnema vespertina type ( Fig. 8C ).

Distribution. Endemic to Madeira.

Figures

FIGURE 1. Hebecnema anthracina Stein. Male terminalia. A, B. Sternites IV and V in ventral and lateral views. C, D. Cerci, surstyli and epandrium in posterior and lateral views.

FIGURE 8. Hebecnema spp. Ovipositor, left half only, except for sternites VI and VII. A, B. H. umbratica (Meigen). C. H. anthracinella sp. nov. Abbreviations: Ce = cercus; Ep = epiproct; Hy = hypoproct; St = sternite; T = tergite.