Merodon trianguloculus Vujic, Likov & Radenkovic sp. nov. Figs 23A-D, 33A-C, 34A-C

Diagnosis.

Medium sized (7.5-11.6 mm), dark brown species with characteristic large silver microtrichose fasciae on terga 2-4 in males (Fig. 23C), and silver michrotrichose ornamentation on scutum in both sexes (Fig. 23A, B); basoflagellomere with rounded apex, 1.6-1.8 times longer than wide in male (Fig. 33A, B).

Description.

Male. Head. Antennae black to dark brown; basoflagellomere rounded, 1.6-1.8 times as long as wide, and ca. 2.3 times as long as pedicel; large fossette dorsomedial and dorsolateral; arista brown and thickened at basal one third, covered with dense microtrichia, ca. 1.8 times as long as basoflagellomere (Fig. 33A, B); face and frons black with gray microtrichia, face covered with dense whitish gray, and frons with yellowish gray pile; oral margin shiny with microtrichose lateral areas; lunule shiny black, bare; vertex covered with gray microtrichia; vertex isosceles, with long, pale whitish yellow pile mixed with black pile on the ocellar triangle; ocellar triangle equilateral; eyes covered with dense pile; occiput with gray-yellow pile, covered with a dense, gray microtrichia; eye contiguity 8-12 facets long.

Thorax. Scutum and scutellum black with bronze luster, covered with dense, erect, yellow pile; scutum with conspicuous silver microtrichose ornamentation (Fig. 23A); posterodorsal part of anterior anepisternum, posterior anepisternum (except anteroventral angle), anterior anepimeron, dorsomedial anepimeron, and posterodorsal and anteroventral parts of katepisternum with long, pale yellow pile and grayish microtrichia; wings entirely covered with microtrichia; wing veins brown; calypteres and halteres pale yellow; legs mostly black, except yellowish tip of femora, basal and apical part of tibiae and brown tarsi ventrally; pile on legs pale yellow; metafemur moderately incrassate, ca. four times longer than wide; pile on metafemur long, and ca. half to two thirds of width of metafemur.

Abdomen. Tapering, 1.2 times longer than mesonotum; terga dark, with broad silver microtrichose fasciae; tergum 2 with pale orange lateral maculae; pile on terga all yellow (Fig. 23C); sterna dark brown, covered with long whitish yellow pile.

Male genitalia. Apical part of anterior surstyle lobe rhomboid shape, approximately as long as wide, covered with dense, short pile (Fig. 34A: al); posterior surstyle lobe oval with basolateral protrusion (lateral hump) (Fig. 34A, B: bp); hypandrium sickle-shaped, without lateral projections; lingula (Fig. 34C: l).

Female. Similar to the male except for normal sexual dimorphism and for the following characteristics: basoflagellomere ca. 1.8 times longer than wide, fossette dorsolateral (Fig. 33C); frons with microtrichose vittae along eye margins; frons covered with mostly gray-yellow pile mixed with black ones; ocellar triangle covered with black pile; ventral margin of metafemur with sparse pilosity, only individual pile longer; lateral side of terga, anterior two third of tergum 2 and all tergum 5 with whitish pile; terga 2-4 with short adpressed black pile medially; microtrichose fasciae on terga 3 and 4 narrower (Fig. 23D).

Etymology.

The name trianguloculus derives from the Latin adjective triangulus (triangular) and Latin noun loculus (spot) and describes the distinctive triangular silver pollinose fasciae on the abdomen.

Distribution.

Merodon trianguloculus sp. nov. was recorded only in Turkmenistan (Fig. 7).

Ecology.

Preferred environment: open areas extending to the forest zone; unimproved grassland; adults resting on the stones and in flight between grasses at the top of Dushak Mountain. Flowers visited: no data. Flight period: May-June.

Type material.

Holotype. Turkmenistan • ♂; 120 km SW Geok-Tepe town; 38°10'31"N, 57°58'01"E; 11 May 1988; A. Barkalov leg.; SZMN 05818. Original label: "HOLOTYPE of Merodon / trianguloculus Vujić, Likov / et Radenković sp.n. 2019" [red label], “Туркмения, I20 км / юз Геок-Тепе 11. У . I988 / Сб.А . Баркалов”, “05818” (See Supplementary file 5: Figure 5). Paratypes. Turkmenistan • 1 ♀; 15 km k-s pos. Firjuza settlement, Dushak Mountain; 18 May 1988; A. Barkalov leg.; SZMN 05819 • 1 ♀; same data as for preceding; SZMN 05837 • 1 ♀; Centr. Kopetdag g. Dušak; 2100-2300 m a.s.l.; 6 Jun. 1986; Dubatolov leg.; SZMN 05844 • 1 ♂; Firjuza settlement 15 km zap., Dushak Mountain; 16 May 1988; A. Barkalov leg.; SZMN 05816 • 1 ♂; same data as for preceding; 8 May 1987; SZMN 05840 • 1 ♂; 120 km SW Geok-Tepe town; 38°10'31"N, 57°58'01"E; 11 May 1988; A. Barkalov leg.; SZMN 05817.