Euthycerina uachi, Mortelmans & Hendrix, 2020

Mortelmans, Jonas & Hendrix, Jef, 2020, Review of Euthycerina Malloch (Diptera, Sciomyzidae), with description of a new species from Chile, Zootaxa 4786 (3), pp. 381-395 : 382-385

Euthycerina uachi sp. nov. Mortelmans & Hendrix

( Figs 3a , 4a , 5a , 6 g–i, 7a, 8a)

Holotype: Adult 1♂, Llancahue ( Chile) 3 December 2016, at ca 302 m a.s.l., 39,830581° S, 73,144683° W. The male holotype is directly pinned, with the dissected genitalia in a microvial attached to the pin. The original labels from top to bottom: “(Chi) Llancahue, -39,830581, -73,144683. 3 XII 2016 ”, “Microvial 5”, “ Holotype Euthycerina uachi Mortelmans & Hendrix 2020 [grey label]”. MNNC.

Paratypes: Adult 3♀, collected in Llancahue ( Chile) on 3 December 2016, at ca 302 m a.s.l., 39,830581° S, 73,144683° W. The female paratypes are directly pinned. The original labels from top to bottom: “(Chi) Llancahue, -39,830581, -73,144683. 3 XII 2016 ”, “ Paratype Euthycerina uachi Mortelmans & Hendrix 2020 [grey label]” . MNNC.

Adult ♀, Valdivia [Arboretum de la Universidad Austral de Chile] ( Chile) on 20 November 2016, at ca 47 m a.s.l., 39,792163° S, 73,262604° W. Directly pinned. The original labels from top to bottom: “(Chi) Llancahue, -39,792163, -73,262604. 20 XI 2016 ”, “ Paratype Euthycerina uachi Mortelmans & Hendrix 2020 [grey label]”. MNNC.

Adult 1♂, collected in the arboretum of Valdivia [Arboretum de la Universidad Austral de Chile] ( Chile) on 17 December 2016, at ca 47 m a.s.l., 39,792163° S, 73,262604° W. Directly pinned. The original labels from top to bot- tom: “(Chi) Arboretum Valdivia, -39,792163, -73,262604. 17 XII 2016 ”, “ Paratype Euthycerina uachi Mortelmans & Hendrix 2020 [grey label]”. MNNC.

Diagnosis. The new species of Euthycerina is a relatively large species for this genus, darker than the other two known species, especially the pleura, occiput, knob of the halter, and scutum. Cell r 1 is devoid of hyaline spots, at most small hyaline spots of which the diameter much less than the height of cell r 1. Frontal vitta wide, always connected to occipital triangle, and always as wide as the occipital triangle. The male terminalia are similar to those of E. pilosa , but the surstyli are much more compressed.

Description. Male. Body length 4.3 mm; wing length 3.45 mm.

Head: Ground color orange yellow, except upper half of occiput, frontal vitta, ocellar triangle, and orbital plates dark brown to black. Heavy whitish pubescence adjacent to the eye margin, surrounding eye except for orbital plate. Pubescence on gena less than half the shiny part, sharply delineated. Frontal vitta dark, depressed, subshining, nearly as broad as ocellar triangle. Frontal vitta continued over ocellar triangle, connecting with black occiput, which shows two elongated silvery pubescent spots ( Fig. 4a ). Face concave in lateral view. Oral margin slightly protruding. Antennae situated slightly above upper fourth of head ( Fig. 5a ). Antennae elongate, squarish. Scape, pedicel, and base of postpedicel brownish yellow, only apical portion of postpedicel dark. Pedicel and postpedicel with dorsal half faintly whitish pubescent. Scape and pedicel with several black setae. Postpedicel with fine black setulae. Pedicel three times as long as scape. Postpedicel three times as long as pedicel. Arista yellow basally, more whitish apically, covered with dense whitish hairs. Arista implanted basally on dorsal margin of postpedicel ( Fig. 8a ). Two pairs of black fronto-orbital setae, anterior pair half as long as posterior pair. Two ocellar setae, two postocellar setae, two outer post-vertical setae, two inner post-vertical setae. Gena and occiput covered with very small black setulae. Palpus yellow with black setulae, proboscis brownish black with white setulae. Lunule exposed only between antennae, pointed anteriorly. Thorax and abdomen: Thorax brownish black with five longitudinal lines of heavy gray pubescence, consisting of a small median line on the anterior half of thorax (position of acrostichal band); two broad submedian lines the entire length of thorax, equally wide over the entire length (position of the dorsocentral band); and two very broad lines situated roughly on the supra-alar band. Mesonotal setae include one pair of postpronotals, two pairs of notopleurals, two pairs of postalars, one pair of presutural pre-alars, one pair of postsutural pre-alars, and two pairs of postsutural dorsocentrals. Pleural area same color as thorax, although a slight yellowish shine is present. Anepisternum and anepimeron bare, katepisternum with several black setae ventrally. Scutellum same color as thorax and pleura, with gray pubescence on dorsocentral strip continuing over scutellum. Two pairs of scutellar setae, one pair basal and one pair apical. Halter yellowish brown, halter knob darkened. Calypter small and dark, margin especially dark, with several long black setae. All pleura with a slight whitish pubescence. Abdomen concolorous with thorax: all sternites and tergites dull brownish, without distinct markings, covered with small black setulae. Tergites with very slight indication of white pubescence, especially medially. Sternites heavily grayish pubescent. Tergite 5 extended ventrally and forming two broadly rounded lobes, these reddish brown in color ( Fig. 6l ). In lateral view, dorsal tip of tergite 5 bent posteriorly, smoothly curved, with tips of left and right lobes meeting over considerable distance ( Fig. 6k ). Legs: Forefemur yellow except apical fifth darkened dorsally. Foretibia black except basal fourth yellow. Foretarsus black except fifth segment yellow. Pulvilli yellow. Claws yellow basally, black apically. Small black setulae distributed evenly over foreleg. Forefemur bearing four large postero-dorsal setae and six smaller ventral setae, foretibia with small subapical seta. Middle and hind legs similar in color: completely yellow, pulvilli yellow and claws yellow basally, black apically. Middle and hind legs completely covered with small black setulae. Midfemur with a medial anterior seta and a double row of 12 strong, short black ventral setae, in apical half of femur only. Midtibia with three subapical setae. Hind femur with two antero-dorsal setae and a double row of 12 strong, short black ventral setae, strongly developed especially apically.All coxae brownish yellow and heavily white pubescent, especially forecoxa. All coxae with several strong black setae. Wing: Black in ground color, with several evenly distributed small, transparent spots. Cell r 1 completely black, with only very faint transparent spots basally. Costal cell completely white. Cell r 2+3, cell r 4+5, cell dm, cell br, cell cua 1, and cell m all with two rows of equal-sized spots. Cell cu p and cell cua 2 dark. Vein A 1 +CuA 2 reaching wing margin. Veins black except vein Sc yellow ( Fig. 3a ). Genital apparatus: Posterior surstyli broad basally, stockier and more compressed than in other species. Posterior surstyli in lateral view tapered to very acute, hooked apex ( Figs. 6i, j ). Posterior surstyli articulating with epandrium. Epandrium elongated, cerci not extended beyond lower margin of epandrium.

Female. Similar to male although general color darker, especially on legs and wings. Tergite 5 normal, not extended ventrally. Mid- and hind femora without a double row of small, black setae.

Etymology. The species is named E. uachi (pronounced [wɑtʃi]), after the Universidad Austral de Chile (UACh). All specimens of E. uachi were found on the campus of the university.

Distribution. For now, E. uachi is known from only two locations, both in Chile and close to each other. The locations are near the city of Valdivia in the region Los Ríos at elevations between 47 and 300m.

Ecology. The type locality of E. uachi consists of dry, flower-rich meadows. It is noteworthy E. pilosa has been collected in the same environments to E. uachi (in both the arboretum and Llanquihue), whereas no other Sciomyzidae were seen here.

Figures

FIGURE 3. Wings of (A) the male holotype E. uachi, (B) the male paratype E. pilosa, and (C) the male paratype of E. vittithorax.

FIGURE 4. Head in dorsolateral view of (A) the male holotype of E. uachi, (B) a male specimen of E. pilosa, and (C) the male paratype of E. vittithorax. Because we had no type material of E. pilosa that included a head, a typical specimen was chosen for this photograph. In addition to the frontal vitta, note the arista, the back of the head, and the color of the scutum, all of which are diagnostic characters.

FIGURE 5. Habitus in lateral view of (A) the male holotype of E. uachi, (B) the male paratype of E. pilosa, and (C) the male paratype of E. vittithorax.

FIGURE 6. Male terminalia of (A–D) the male paratype of E. pilosa; (E–H) the male paratype of E. vittithorax; (I–L) the male holotype of E. uachi. Male terminalia, posterior view (A, E, I); male terminalia, lateral view (B, F, J); male tergite 5, lateral view (C, G, K); male tergite 5, ventral view (D, H, L). Each facet on a row is drawn on the same scale, and the corresponding scale bars indicate 0,5mm.

FIGURE 8. Lateral view of the antennae of the male holotype of E. uachi (A), the male paratype of E. pilosa (B), and the male paratype of E. vittithorax (C).