Merodon nisi, Veselić, Sanja, Vujić, Ante & Radenković, Snežana, 2017

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 : 418-424

Merodon nisi sp. n.

Figs 3 c, 11, 17–19, 20a

Type material. HOLOTYPE: Greece: ♂, Rhodes , Kalathos (Lindos), 15.x.2012, leg. A. Vujić ( FSUNS) . PARATYPES: Greece: ♂, ♀, Rhodes , Genadi, 23–27.x.1988, leg. H. Teunissen ( RMNH) .

Diagnosis. Small species with very short body pilosity ( Figs 17 a, 19a); hind tibia ( Figs 17 b, 20a) with dark brown to black submedial ring and tarsi of hind leg darkened dorsally (in the M. bessarabicus subgroup this character is present only in some specimens); tergite II with a pair of small, rounded, lateral, reddish spots ( Figs 17 a, 19a).

Body size. Length: body = 6–9 mm; wing 4–6 mm (n = 3).

Description. MALE ( Fig. 17 , 18 ). Head ( Fig. 17 c, 17d). Antenna brown; basoflagellomere 1.3–1.5 times longer than pedicel, dorsal margin concave between the arista and the apex, apex acute; arista light brown basally, as long as pedicel and basoflagellomere together. Face and frons shiny black, with indistinct microtrichose medial facial stripe and microtrichose line along eye margin; covered with whitish pile, except for some intermixed black ones in the upper part of frons. Oral margin bare, black and lustrous. Vertical triangle isosceles, 2.5 times longer than eye contiguity, shiny black and covered in long black pile. Eye contiguity about 8–10 ommatidia long, with a tendency for eyes to be separated. Ocellar triangle equilateral, covered with black pile. Eye pile short, predominately black over the entire surface, except for a postero-ventral corner of pale pile. Occiput shiny, bluish green, except for stripe of white microtrichia along eye margin; covered in whitish pile. Thorax. Mesonotum black with metallic bronze reflections, covered in short, mixed black and light yellow pile; black pile concentrated in the area between wing bases ( Fig. 18 a, 18b); scutellum predominately covered with sparse, short, black pile, except light yellow pile laterally; mesoscutum with three weak longitudinal stripes of dark brown to black microtrichia in anterior half. Posterior anepisternum, anepimeron and dorsal part of katepisternum with whitish-yellow long pile. Wing brown-greyish, with dark brown veins; spurious vein at the level of bm-cu with spot of dark brown to black microtrichia; pterostigma light brown; completely covered with brown microtrichia except for the following areas with reduced microtrichia: cell bc, proximal half of cell br above and below vena spuria, proximal end of cells bm and cup, small central part of alula. Dorsal and ventral calypters light yellow. Haltere with yellow pedicel and brown capitulum. Femora black, except pale apex; fore and mid femora covered posteriorly with long light yellow pile and both dorsally and anteriorly with short black pile. Hind femur with light yellow pile basally and anteriorly, and with many black pile apically and posteriorly ( Fig. 18 c). Fore and mid tibiae pale with more or less conspicuous submedial brownish ring; hind tibia pale in basal half and apically ( Fig. 17 b). Tarsi pale, except for three dark brown, apical tarsomeres in fore and mid legs dorsally (the darkest is tarsomere IV), and all tarsomeres of hind leg dorsally covered in yellow and black pile ( Fig. 17 b). Hind trochanter with an inner spike ending in two angular points. Abdomen. Oval, slightly longer than mesonotum; extensively black, dull without metallic reflections ( Fig. 17 a). Tergites II and III with weak white transverse bands of microtrichia interrupted in the middle. Tergite II with a pair of small, orange translucent, oval, lateral spots ( Fig. 17 a). Tergite I and area that covers lateral spots and microtrichose stripes on tergite II with pale pile, remaining tergites predominately covered with black pile, except for pale pilosity on lateral sides. Central part of tergites covered with very short and adpressed pile. Sternites dull; covered with long light yellow pile, except for posterior half of sternite IV with many black pile. Genitalia. Similar to all other species of the aureus group.

FEMALE ( Fig. 19 ). Similar to the male except for normal sexual dimorphism and in the following characteristics: frons covered with more black pile than in male, especially in central part ( Fig. 19 b). Hind trochanter without spike. Abdomen with a pair of white bands of microtrichia on tergites II and III and, in some specimens, also on tergite 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. 19 a).

Etymology. The word nisi means ‘island’ in Greek, and refers to the type locality of this species, i.e. the Aegean island of Rhodes.

Range and preferred habitat. Rhodes island ( Greece) ( Fig. 11 ); open, grassy areas in pine forest or Mediterranean scrub.

Figures

FIGURE 3. Diagnostic characters, males: a— Merodon adriaticus sp. n., thorax and abdomen, dorsal view (scale 1 mm); b— Merodon ambiguus, hind tibia, lateral view (scale 0.5 mm); c— Merodon nisi sp. n., hind tibia, lateral view (scale 0.5 mm).

FIGURE 11. Distribution of Merodon nisi sp. n. (●), Merodon robustus sp. n. (■) and Merodon quercetorum (▲).

FIGURE 17. Merodon nisi sp. n., male: a—dorsal view (scale 1 mm); b—hind leg, lateral view (scale 0.5 mm); c—head, lateral view (scale 0.5 mm); d—head, anterior view (scale 0.5 mm).

FIGURE 18. Merodon nisi sp. n., male: a—thorax, dorsal view; b—thorax, lateral view (anterior part of the thorax on the right side, posterior part on the left side); c—hind femur and tibia, lateral view. Scale 0.5 mm.

FIGURE 19. Merodon nisi sp. n., female: a—dorsal view (scale 1 mm); b—head, anterior view (scale 0.5 mm).