Psilota alexanderi Young, 2020

Young, Andrew D., Skevington, Jeffrey H. & Steenis, Wouter Van, 2020, Revision of the Psilota Meigen, 1822 flower flies (Diptera: Syrphidae) of Australia, Zootaxa 4737 (1), pp. 1-127 : 24

Psilota alexanderi Young sp. nov.

( Figs 1–4 ; Species plate: Fig. 6 ; Genitalia: Fig. 40 A–B; Map: Fig. 50B )

Diagnosis: Metallic blue species with frons pale pilose, pleuron shining and partly white pilose. Hind femur with a distinct rounded apicoventral setulose carina. Hind tibia with a basoventral spur. Calypter entirely dark brown, with pile on the border of the upper calypter white. Tergite 4 black pilose. Body length: 10.2–13.5 mm.

Description: MALE: Head: Head black, face densely pale pollinose. Face and frons yellow pilose, vertex black pilose. Antenna usually entirely orange, rarely dull brown dorsally on postpedicel. Eye densely yellow pilose.

Thorax: Thorax dark, metallic blue. Legs entirely dark, somewhat metallic blue. Hind femur with a distinct rounded apicoventral setulose carina Hind tibia with a small basoventral spur. Pleuron shining, pollinosity free. Pile on pleuron almost entirely white, sometimes with a few black pile on the posterior anepisternum, anepimeron, and/or the ventral half of the katepisternum. Pile scutum and scutellum entirely black. Wing colourless, with cells c, r, bm, cua, and the anal lobe mostly bare. Cells r 4+5, r 2+3, and dm with bare areas basally. Alula completely microtrichose. Halter dark brown. Calypter entirely dark brown, with pile on the border of the upper calypter contrasting white. Abdomen: Abdomen dark metallic blue. Tergites with pile very short. Tergite 2 with white pile on basal half and black pile on apical half, tergite 3 with pile almost entirely black, with only anterior rim of tergite while pilose, tergite 4 entirely black pilose. Sternites shining, white pilose. Genitalia: Epandrium compact, about as long as tall. Cercus approximately triangular. Outer lobe of surstylus inserted just above mid-height of inner lobe, curve downwards sharply at one-quarter its length, curving smoothly back towards base of surstylus, thinning at apex. Inner lobe of surstylus subrectangular, approximately 4 times as long as high, rounded at apex. Phallapodeme with small, broad ventral projection. Gonostylus broad, no darker than remainder of genitalia.

FEMALE: Identical except for normal sexual dimorphism.

Etymology: This species is named for Alexander Skevington, who co-collected part of the type series. Though young in years, Alexander is already an avid field biologist and nature photographer.

Specimens examined: HOLOTYPE: AUSTRALIA: Western Australia: Summit of Mount Barker , -34.655691 117.647081, hilltop, 26.I.2015, J.H., A.M. and A.W. Skevington; CNC391294 , (1♂, ANIC) . PARATYPES: Western Australia: Same data as holotype: CNC391293 ; CNC391295-391298 (5♂♂, CNC) ; Capel District, 18 miles South of Bunbury, -33.510783 115.641533, 1957, A. Snell, AustralianMuseumK406918; AustralianMuseumK410288 (2♂♂, AM) ; Foothills, Kelmscott , -32.119000 116.026000, 21.X.1958, J. Baldwin, SAMADatabaseNo.29-003351 (1♂, SAMA) ; K.G.P., AustralianMuseumK410289 (1♀, AM); Stirling NP n. side of range, -34.399117 117.962769, ex: Eucalyptus , 25.xii.1994, LS & RB Kimsey, CNC _ Diptera 255000 (1♀, CNC); Porongorup National Park, Summit of Morgan’s View , -34.680161 117.868214, hilltop, 25.i.2015, J.H., A.M. and A.W. Skevington, CNC451880 (1♂, CNC) ; Summit of Mount Barker , -34.655692 117.647083, hilltop, 26.i.2015, J.H., A.M. and A.W. Skevington, CNC452068-452069 (2♂♂, CNC) .

Discussion: This western species has been collected hilltopping on Mount Barker. The hilltop is dominated by dry sclerophyll forest and has a communications tower on it. The habitat around the hilltop is largely agricultural. Psilota alexanderi sp. nov. adults were all on an elevated rise just west of the communications array. This summit of the rise is rocky and open with Eucalyptus trees around the clearing. The flies were hovering about 3–4m above the rocks along the edge of this clearing.

Figures

FIGURE 1. Psilota alexanderi sp. nov., general habitus. Illustration by Jessica Hsiung.

FIGURE 2. Psilota alexanderi sp. nov., dorsal habitus. Illustration by Jessica Hsiung.

FIGURE 3. Psilota alexanderi sp. nov., lateral habitus. Illustration by Jessica Hsiung.

FIGURE 4. Psilota alexanderi sp. nov., genitalia lateral. Illustration by Jessica Hsiung.

FIGURE 6. P. alexanderi sp. nov., A) male dorsal habitus, B) male anterolateral face, C) male lateral habitus. Scale bar =1 mm.

FIGURE 40. Lateral and dorsal male genitalia of A, B) P. alexanderi sp. nov.; C, D) P. apiformis sp. nov.; E, F) P. auricauda Curran, and G, H) P. auripila sp. nov.. Scale bar =1 mm.

FIGURE 50. Known range of A) P. aislinnae sp. nov.; B) P. alexanderi sp. nov.