Merodon flavicornis Macquart

Veselić, Sanja, Vujić, Ante & Radenković, Snežana, 2017, Three new Eastern-Mediterranean endemic species of the Merodon aureus group (Diptera: Syrphidae), Zootaxa 4254 (4), pp. 401-434 : 408-411

Merodon flavicornis Macquart

Figs 6–8 , 16 c

Macquart (1842: 71) described this species from an unknown locality. In the Macquart collection (MNHN), Thompson (1988) recognized a headless male holotype labelled as "No. 1184, Merodon flavicornis ". He concluded that this holotype was conspecific with Merodon aureus and proposed a new synonymy. The holotype of Merodon flavicornis shares the same morphological features as other French specimens that the authors of the present paper examined in different collections and which were found to be different to Merodon aureus . Thus, M. flavicornis is recognized here as a valid Western Mediterranean species.

Type material. (revised). HOLOTYPE: ♂, "no. 1189" Vockeroth designated as holotype 1969, (MNHN).

New records. France: ♂, Castellet, Le Beausset (Var), 07.x.1918, leg. Ancey Seguy ( MNHN) ; ♂, Le Market, 07.X.1918 (MNHN); ♀, Provence Alpes Cote d'Azur, Var, Montauroux, 06.ix.1961, leg. J. v.d Vecht (RMNH); 1 ♀, Gard, Anduze, leg. A. Boucomont (MNHN).

Diagnosis. Species with completely pale tibiae and tarsi; mesoscutum covered with pale pile; shiny tergites, with golden-bronze reflection, covered with light yellow hairs ( Fig. 7 a); tergites in male usually without microtrichia; eye pile in male black in upper 1/3 (contrary to M. legionensis black in upper 1/2); tarsi light (in M. legionensis apical tarsomeres darkened); pale pilosity on tergite V in female (in M. legionensis predominately black) and distribution (restricted to France) separate this taxon from the related Western Mediterranean species, M. legionensis (Iberian Peninsula).

Body size. Length: body = 8–11 mm; wing 6–9 mm (n = 4).

Re-description. MALE ( Fig. 7 ). Head ( Fig. 7 b, 7d). Antenna from orange to yellowish; basoflagellomere yellow, 1.3–1.5 times longer than pedicel, dorsal margin concave between the arista and the apex, apex acute; arista orange-yellow basally, brown apically, as long as pedicel and basoflagellomere together. Face shiny black, frons duller, with greenish film; covered with long whitish-yellow pile and scarce indistinct grey microtrichia. Oral margin bare, with black lustre. Vertical triangle isosceles, twice as long as eye contiguity, shiny black, predominately covered with long yellow pile, except for black ones anteriorly. Eye contiguity about 18 ommatidia long. Ocellar triangle equilateral, with pale and black pilosity. Eye pile black in upper 1/3; light yellow pile dominate in central and lower parts. Occiput shiny, silver-green, except along eye margin with a narrow stripe of white microtrichia; covered with yellow pile. Thorax. Mesonotum black, with green-bronze reflections, covered in long, dense, erect yellowish pile ( Fig. 7 a); mesoscutum with three very weak longitudinal stripes of golden microtrichia in anterior half. Posterior anepisternum, anepimeron and dorsal part of katepisternum with long yellowish pile. Wing yellowish, with light brown veins. Dorsal and ventral calypters light yellow. Haltere with yellow pedicel and light brown capitulum. Femora mostly black, except for pale base and apex. Fore and mid femora covered with long yellow pile posteriorly, the rest with short black pile. Hind femur predominately with pale pilosity and a few black pile apically ( Fig. 7 c). All tibiae and tarsi pale, covered in yellow pile ( Fig. 7 c). Hind trochanter with an angular inner spike. Abdomen. Oval, slightly longer than mesonotum; black with golden-bronze reflections. Tergites II–IV dark brown to black and usually without white transverse bands of microtrichia ( Fig. 7 a). Tergites completely covered with pale pile. Sternites shiny brown, covered with long light yellow pile. Genitalia. Similar to all other species of the aureus group.

FEMALE ( Fig. 8 ). Similar to the male except for normal sexual dimorphism and the following characteristics: frons shiny black. Vertex mostly covered with black pile except for posterior end with yellow ones ( Fig. 8 b). Hind trochanter without spike. Abdomen shiny black, with a pair of white bands of microtrichia on tergites II–IV. On tergite II these bands are subparallel to the anterior margin of the tergite, whereas on tergites III and IV these bands are oblique ( Fig. 8 a). Tergites partly covered in pale pile; black pile present in central parts of posterior half of tergite II, all of tergite III and anterior half of tergite IV, except on mictrotrichose stripes; tergite V covered in yellow pile with some intermixed black ones.

Range and preferred habitat. France ( Fig. 6 ); thermophilous Quercus forest.

Figures

FIGURE 6. Distribution of Merodon d flavicornis (●) and Merodon d legionensis (▲).

FIGURE 7. Merodon flavicornis, male: a—dorsal view (scale 1 mm); b—head, lateral view (scale 0.5 mm); c—hind leg, lateral view (scale 0.5 mm); d—head, anterior view (scale 0.5 mm).

FIGURE 8. Merodon flavicornis, female: a—dorsal view (scale 1 mm); b—head, anterior view (scale 0.5 mm).

FIGURE 16. Females: a— Merodon rufipes, thorax, lateral view (anterior part of the thorax on the right side, posterior part on the left side); b— Merodon legionensis, hind tarsi, lateral view; c— Merodon flavicornis, hind tarsi, lateral view. Scale 0.5 mm.