Peradon ballux Reemer

Reemer, Menno, Skevington, Jeffrey H. & Kelso, Scott, 2019, Revision of the Neotropical hoverfly genus Peradon Reemer (Diptera, Syrphidae, Microdontinae), ZooKeys 896, pp. 1-93 : 1

Peradon ballux Reemer sp. nov. Figs 80 , 95 , 145 , 165-167 , 282

Type material.

Holotype. Argentina • 1 ♂, holotype of Peradon ballux sp. nov.; Misiones, 5 km E Puerto Iguazo, behind Hotel Orquidaes; 6 Feb. 1992; S.A. Marshall leg.; DEBU.

Label 1: "Argentina: Misiones / 5 km E Puerto Iguazo / behind Hotel Orquidaes / 1-6.ii.1992 / S.A. Marshall"; label 2: "Peradon sp. 02 / det. M. Reemer 2016 / Voucher code MR715".

Additional specimens.

Brazil • 1 ♂; Paraná, Piraquara, Mananciais da Serra, Mar; 25°29'46"S, 48°58'54"W; 6 Dec. 2007; J.A. Rafael leg.; INPA (INPA-DT0000058).

Description

(based on holotype). Adult male. Body size: 8 mm.

Head. Face occupying 0.47 of head width in frontal view; black, except for pale yellow, oblique vittae laterally on ventral half; white pilosity, more golden medially. Gena black with white pilosity. Lateral oral margin weakly produced; black with white pilosity. Frons and vertex black with golden pilosity, except ocellar triangle with black pilosity. Occiput black with golden pilosity dorsally, white pilosity ventrally. Eye bare. Antennal fossa approx. as wide as high. Antenna brown. Ratio scape:basoflagellomere approximately 1:1. Basoflagellomere parallel-sided with rounded apex. Arista slender, ca. 3/5 of length of basoflagellomere.

Thorax. Mesoscutum dull black; short, appressed black pile, except for narrow fasciae of pale golden pile along anterior margin, transverse suture, and posterior margin. Postpronotum brown; bare. Postalar callus brown; golden pilosity. Scutellum black with faint metallic green hue, posterior margin brownish; short yellow pilosity; with two apical calcars of ca. 1/6 of length of scutellum, with mutual distance slightly more than 1/2 length of scutellum. Pleura blackish brown. Anterior and posterior part of anepisternum separated by deep sulcus; golden pilosity anteriorly, whitish pile posteriorly, with wide bare area in between. Anepimeron entirely whitish pilose. Katepisternum white pile dorsally, bare ventrally. Other pleura bare (except for microtrichiae). Calypter whitish with yellow margin. Halter yellow.

Wing. Hyaline, except for pale yellow macula in basal half of cell r2+3, with dark veins, except veins c and R1 yellow between wing base and stigmal crossvein. Wing microtrichose, except bare on posterobasal 5/6 of br, basal 3/4 of bm, anterobasal 1/4 of cup, and most of alula (only microtrichose along margins).

Legs. Brownish black with faint metallic hues; white pilosity, except tarsi and tibiae ventrally dark golden pilosity.

Abdomen. Elongate, widest at middle of tergite 3, although this tergite almost parallel-sided; blackish brown, except pale brown on lateral margins of tergites 3 and 4, and largely golden metallic medially on tergite 4; tergite 1 white pilosity; tergites 2 and 3 short black pilosity, except short golden to white pilosity along lateral margins; tergite 4 golden pilosity with narrow median vitta of short black pile. Sternites blackish brown; white pilosity, except sternite 1 bare.

Female. Unknown.

Diagnosis.

Body length: male 8-9 mm. The conspicuous golden pile on tergite 4 places this species in the flavofascium species group. Within this group, this species is distinguished by the combination of the following characters: basoflagellomere longer than scape, postpronotum bare, wing cell c bare on posterobasal 1/4 or less, alula largely bare, wing cell r4+5 without yellow colouration. Male genitalia as in Fig. 282 .

Notes.

The additionally studied male specimen from Brazil ( Paraná) differs from the holotype in its larger body size (9 mm), slightly smoky wings, and the presence of a pair of submedian vittae of black pile on tergite 4. Possibly, this specimen belongs to another species, which is why it is not designated as paratype. However, the number of available specimens is too low to make a decision on this.

Distribution.

Known from the Argentinian province Misiones and the Brazilian state of Paraná.

Etymology.

The Latin word ballux means gold-dust, and this was chosen as specific epithet in reference to the golden pilosity of tergite 4. It is to be treated as a noun in apposition.

Figures

Figures 74 - 85. Wings of Peradon species of the flavofascium - group 74 P. flavofascium ♂ holotype 75 P. flavofascium ♀ 76 P. surinamensis ♂ holotype 77 P. surinamensis ♀ Suriname RMNH 78 P. aurigaster ♂ holotype 79 P. aurigaster ♀ Peru CNC 80 P. ballux ♂ holotype 81 P. brevis ♂ holotype 82 P. notialus ♂ holotype 83 P. notialus ♀ paratype 84 P. chrysopygus ♂ Costa Rica RMNH 85 P. chrysopygus ♀ Belize MZH.

Figures 90 - 96. 90, 91 Scutellum: 90 P. flavofascium male (holotype) 91 P. surinamensis male (holotype) 92 - 96 Mesonotum: 92 P. flavofascium female (Brazil MZUSP) 93 P. surinamensis female (paratype) 94 P. notialus male (holotype) 95 P. ballux male (holotype) 96 P. brevis male (holotype).

Figures 143 - 148. Dorsal habitus of Peradon species (flavofascium group) 143 P. aurigaster ♂ Bolivia RMNH 144 P. aurigaster ♀ Peru RMNH 145 P. ballux ♂ holotype 146 P. notialus ♂ holotype 147 P. notialus ♀ paratype 148 P. brevis ♂ holotype. Scale bar: 10 mm.

Figures 165 - 170. Peradon ballux male, holotype: 165 habitus lateral 166 head frontal 167 head lateral 168 - 170 Peradon bidens male, holotype 168 head frontal 169 habitus dorsal 170 habitus lateral

Figures 280 - 283. Male genitalia of Peradon species 280 P. brevis holotype 281 P. chrysopygus Costa Rica RMNH 282 P. ballux holotype 283 P. aurigaster Bolivia RMNH.