Stigmaporus volgadon Loktionov & Lelej

Loktionov, Valery M., Lelej, Arkady S. & Mokrousov, Mikhail V., 2016, Review of the genus Stigmaporus S. Zonstein, 2001 (Hymenoptera: Pompilidae), with description of new species, Zootaxa 4126 (1), pp. 107-114 : 110-114

Stigmaporus volgadon Loktionov & Lelej , sp. nov.

( Figs 1, 2 –20, 32, 33)

Type material. Holotype, ♂, Russia, Volgograd Prov., 18 km NNE Kalach-na-Donu, Ryumino-Krasnoyarskiy, 12.VII.2015 (V. Loktionov, M. Proshchalykin, M. Mokrousov) [48°51'27.53"N, 43°38'2.24"E]. Paratypes, 1 ♀, same label; 1 ♀, 1 ♂, Russia, Astrakhan Prov., environments of Zam'yany, 22.VIII.2015 (M. Mokrousov) [46°48'57.58"N, 47°36'58.46"E].

Diagnosis. Female and male. Abscissa Rs1 of hind wing shorter than vein rs-m ( Figs 15, 17 ) (♀ ♂). Marginal cell of fore wing (along wing margin) noticeably longer than pterostigma (♀ ♂); distance between 2rs-m and inner margin of dark apical spot less than maximum width of cell 1Rs ( Figs 14, 16 ) (♀ ♂). Spines of tarsal comb weakly broadened preapically, preapical spine of protarsomere 4 needle-like (Fig. 32) (♀). Apical margin of hypopygium narrowly oval (Fig. 19) (♂). Paramere of genitalia basally with long bristles (Fig. 18) (♂).

Description. FEMALE. Length: body 4.7−5.2 mm; fore wing 3.8–4.7 mm. Head. Width of head 1.2 × its height ( Fig. 8 ). Ocelli small, ratio POD/OOD 1.2 ×. Width of gena medially 0.38–0.41 × width of eye medially (lateral view). Half of middle interocular distance 1.25–1.32 × eye width. Vertex straight medially and gently rounded laterally ( Fig. 10 ). Clypeus weakly longitudinally convex, anterior border broadly rounded, with narrow smooth rim lacking pubescence. Mandible narrow and long pointed apically, with two distinct inner teeth. Malar space 0.35–0.40 × pedicel width. Relation of scape, pedicel and two first flagellomeres 22–25:11–12:29–36:27–34. Flagellomere 1 4.7–4.8 × as long as wide. Apical flagellomere distinctly obliquely truncated apically, with flat polished area.

Mesosoma. Mesosoma dorsally 2.1–2.2 × as long as maximum wide. Pronotum dorsally almost parallel-sided; pronotum medially 0.4 × as long as wide; pronotum posterad rounded, indistinctly angulate medially ( Fig. 10 ). Metanotum medially 1.2–1.4 × as long as metapostnotum medially ( Fig. 6 ). Propodeum medially 0.9–1.0 × as long as maximum wide.

Legs. Relation of protarsomeres 33–36:16–22:14–17:11–12:17–20. Protarsomere 1 with 4 retrolateral flattened spines weakly broadened preapically and 2–3 needle-like spines; apical retrolateral spine 1.5–1.6 × as long as protarsomere 2, and 5.0 × as long as maximum width of protarsomere 1. Protarsomeres 2 and 3 with 2 flattened weakly broadened preapically spines; apical spine of protarsomere 2 1.6 × as long as protarsomere 3; apical spine of protarsomere 3 1.4–1.5 × as long as protarsomere 4. Protarsomere 4 with one needle-like spine. Tarsal claws bifid and symmetrical ( Fig. 13 ).

Wings. Fore wing slightly infuscated with darker apical part, venation as in Fig. 14 . Hind wing regularly slightly infuscated, venation as in Fig. 15 .

Sculpture. Head, mesosoma and metasoma subpolished. Metapostnotum shiny, with fine transverse striae. Antenna (except polished apical area of apical flagellomere) and legs matte.

Colour and pubescence. Head black; inner eye orbit with small yellow spot; anterior rim of clypeus brown; basal half of mandible yellowish, apical half brown; antennae black with scape ventro-apically yellow; ocelli brown. Mesosoma black; posterior border of pronotum yellowish. Metasoma mostly brownish; T1 baso-dorsally, T4, T5 basally and S6 dark brown; other metasomal segments brown or light brown. Procoxa, profemora and protibia mostly black; meso- and metacoxa, trochanter and basal half of femur black, apical part of femur and tibia light brown; tarsi brown; spines of tarsal comb and tibial spurs pale yellow; coxae apically with small yellow spots. Upper frons, vertex, gena, clypeus, propleuron, pronotum with long white erect setae. Propodeum laterally with few white setae, shorter than those of vertex, or without setae. S6 and T6 with long light brown erect setae. Head, mesosoma and coxae with dense silver-white pubescence ( Fig. 4 ). Scape, legs (except coxa) and metasoma with sparse white pubescence. Metapostnotum without pubescence.

MALE. Length: body 3.8–5.8 mm; fore wing 2.9–4.3 mm. Head. Width of head 1.1 × its height ( Fig. 9 ). Ocelli small, ratio POD/OOD 1.2–1.3 ×. Width of gena medially 0.30–0.36 × width of eye medially (lateral view). Half of middle interocular distance 1.4–1.5 × eye width. Vertex straight medially and gently rounded laterally ( Fig. 11 ). Clypeus weakly longitudinally convex, anterior border broadly rounded. Mandible narrow and long pointed at apex, with two distinct small inner teeth. Malar space 0.3–0.5 × pedicel width. Relation of scape, pedicel and two first flagellomeres 15–20:7–10:13–21:15–24. Flagellomere 1 2.4–2.7 × as long as wide. Apical flagellomere distinctly obliquely truncated apically, with polished area.

FIGURES 18–35. 18–20, 32, 33. Stigmaporus volgadon sp. nov. (18–20. Holotype; 32, 33. Paratypes). 21–23, 26–29, 34, 35. S. wolfi (S. Zonstein) . 24, 25. S. lystracantha (Wolf) . 30, 31. S. centralasiaticus (Wolf) . 18. Genitalia, ventral view. 19, 22. S8 (hypopygium), ventral view. 20, 23. S8, lateral view. 21. Genitalia, left ventral, right dorsal view. 24, 26, 28, 30. Fore wing. 25, 27, 29, 31. Hind wing. 32–35. Protarsomeres 1–4. 18–23, 28, 29, 33, 35. Ƌ. 24–27, 30, 31, 32, 34. ♀. Scale bar for 18–20 = 0.2 mm. (21–29, 34, 35 from: S. Zonstein 2001; 30, 31 from: Wolf 1990).

Mesosoma broadened medially (dorsal view); mesosoma dorsally 2.0–2.1 × as long as maximum wide. Pronotum dorsally distinctly narrowed anterad; medially 0.4 × as long as wide; posterior border rounded. Metanotum medially 1.45 × as long as metapostnotum medially ( Fig. 7 ). Propodeum distinctly narrowed posterad; medially 0.9 × as long as maximum width.

Legs. Relation of protarsomeres 21–30:10–15:9–12:7–9:10–14. Protarsomere 1 with 2–3 retrolateral needlelike spines; apical spine 0.9–1.1 × as long as protarsomere 2 and 2.9–3.0 × as long as maximum width of protarsomere 1. Protarsomere 2 with 2 spines; apical spine 1.0–1.2 × as long as protarsomere 3. Protarsomere 3 with 1–2 spines; apical spine 0.6–1.0 × as long as protarsomere 4. Protarsomere 4 without spines. Tarsal claws with strong setae, without distinct inner tooth ( Fig. 12 ).

Wings. Fore wing slightly infuscated with darker apical part, venation as in Fig. 16 . Hind wing regularly slightly infuscated, venation as in Fig. 17 .

Metasoma. S8 (hypopygium) nearly flat (Fig. 20) with narrow-oval apical margin, with short dense setae (Fig. 19). Genitalia as in Fig. 18; basal half of paramere with long bristles; volsella ventrally with scattered bristles.

Sculpture. Head, mesosoma and metasoma subpolished. Metapostnotum shiny with finest indistinct transverse striae. Antennae (except polished apical area of apical flagellomere) and legs matte.

Colour and pubescence. Head black; inner eye orbit with small yellow spot; basal half of mandible yellowish, apical half brown; antenna black with yellow spot on scape ventro-apically; ocelli brown. Mesosoma black; posterior border of pronotum with broad yellow strip; tegula yellow. Metasomal segments black with brown spots. Coxae black with small yellow spots apically. Protrochanter black with yellow ring apically; profemur mostly black with yellow tip; protibia brown with yellow base and tip; protarsomeres brown. Meso- and metatrochanter and basal half of femur black, but apical part of femur and tibia brown; meso- and metatarsus from light to dark brown. Spines of tarsal comb pale yellow. Tibial spurs brown. Body without setae; gena and propleura with long white thin erect setae. Head (except upper frons), mesosoma and coxae with dense silver-white pubescence ( Fig. 5 ). Scape, legs (except coxae) and metasoma with rarer white pubescence. Metapostnotum lacking pubescence.

Comparison. The female of this new species is similar to that of Stigmaporus wolfi ( S. Zonstein, 2001) , but differs by having the flagellomere 1 4.7–4.8 × as long as wide (5.0–5.6 × in S. wolfi ), the metanotum medially 1.2– 1.4 × as long as metapostnotum medially (1.5 in S. wolfi ), the apical spine of protarsomere 1 1.5–1.6 as long as protarsomere 2 (1.2 × in S. wolfi ), by having needle-like spine of tarsal comb on protarsomere 4 (distinctly flattened and broadened preapically in S. wolfi ), the body length 4.7−5.2 mm (6.2–8.0 mm in S. wolfi ). The male of the new species differs from that of S. wolfi by having flagellomere 1 2.36–2.67 × as long as wide (2.1 × in S. wolfi ), the apical spine of protarsomere 1 0.9–1.0 × as long as protarsomere 2 (0.6 × in S. wolfi ); the apical spine of protarsomere 2 1.0–1.2 × as long as protarsomere 3 (0.8 × in S. wolfi ), abscissa Rs1 of hind wing 0.6–0.7 × as long as rs-m, fig. 17 (0.5 × in S. wolfi , Fig. 29), the hypopygium with narrow-oval apical margin, fig. 19 (broad-oval in S. wolfi , fig. 22), the paramere basally with long bristles, fig. 18 (short bristles in S. wolfi (Fig. 21), the basal part of paramere shorter than apical one, fig. 18 (longer than apical one in S. wolfi , fig. 21).

Distribution. South of European part of Russia (Volgograd and Astrakhan Prov.) ( Figs 1–3 ).

Etymology. The specific name originates from the names of the famous rivers Volga and Don, with reference to the locality, where this species is distributed. It is a noun in apposition.

Biology. The species inhabits arid sandy areas ( Fig. 3 ).

Key to the species (based on key from: S. Zonstein 2001)

Females

1. Abscissa Rs1 of hind wing as long as, or slightly longer than rs-m (Fig. 25)....................... S. lystracantha (Wolf) - Abscissa Rs1 of hind wing shorter than vein rs-m ( Figs 15 , 27, 31).............................................. 2 2. Marginal cell of fore wing (along wing margin) noticeably shorter than pterostigma; distance between 2rs-m and inner margin of dark apical spot much more than maximun width of cell 1Rs (Fig. 30)...................... S. centralasiaticus (Wolf) - Marginal cell of fore wing (along wing margin) noticeably longer than pterostigma; distance between 2rs-m and inner margin of dark apical spot less than maximum width of cell 1Rs ( Figs 14 , 26)............................................ 3 3. Flagellomere 1 5.0–5.6 × as long as wide. Metanotum medially 1.5 × as long as metapostnotum medially. Apical spine of protarsomere 1 1.2 × as long as protarsomere 2 (Fig. 34). Spines of tarsal comb strongly broadened preapically, including preapical spine of protarsomere 4 which flattened and distinctly broadened (Fig. 34).................... S. wolfi (S. Zonstein) - Flagellomere 1 4.7–4.8 × as long as wide. Metanotum medially 1.2–1.4 × as long as metapostnotum medially. Apical spine of protarsomere 1 1.5–1.6 × as long as protarsomere 2 (Fig. 32). Spines of tarsal comb weakly broadened preapically, ecxept preapical spine of protarsomere 4, which needle-like (Fig. 32).................. S. volgadon Loktionov & Lelej , sp. nov.

Males (unknown for S. centralasiaticus )

1. Abscissa Rs1 of hind wing as long as, or slightly longer than rs-m (as in Fig. 25).................. S. lystracantha (Wolf) - Abscissa Rs1 of hind wing shorter than vein rs-m ( Figs 17 , 29)................................................. 2 2. Flagellomere 1 2.1 × as long as wide. Apical spine of protarsomere 1 0.6 × as long as protarsomere 2; apical spine of protarsomere 2 0.8 × as long as protarsomere 3 (Fig. 35). Abscissa Rs1 of hind wing 0.5 × as long as rs-m (Fig. 29). Apical margin of hypopygium broad-oval (Fig. 22). Basal half of paramere with shorter bristles (Fig. 21)............. S. wolfi (S. Zonstein) - Flagellomere 1 2.4–2.7 × as long as wide. Apical spine of protarsomere 1 0.9–1.0 × as long as protarsomere 2; apical spine of protarsomere 2 1.0–1.2 × as long as protarsomere 3 (Fig. 33). Abscissa Rs1 of hind wing 0.6–0.7 × as long as rs-m ( Fig. 17 ). Apical margin of hypopygium narrow-oval (Fig. 19). Basal half of paramere with longer bristles (Fig. 18).................................................................................... S. volgadon Loktionov & Lelej , sp. nov.

Figures

FIGURES 1 – 3. 1. Distribution of Stigmaporus species. 2. Map of Russia (part) with the localities of S. volgadon sp. nov. (a, Volgograd Prov.; b, Astrakhan Prov.; EUR, European part; UR, South Ural; WS, West Siberia; ES, East Siberia). 3. The locality of S. volgadon sp. nov. (Volgograd Prov., Golubinskye Sands). (2 from: Loktionov & Lelej 2015; 3 from: Google Earthhttps: // earth. google. com /).

FIGURES 4 – 17. Stigmaporus volgadon sp. nov., Ƌ (holotype) and ♀ (paratype from Volgograd Prov.) 4, 5. Habitus. 6, 7. Scutellum, metanotum, metapostnotum and propodeum, dorsal view. 8, 9. Head, frontal view. 10, 11. Head and pronotum, dorsal view. 12. Mesotarsal claw. 13. Metatarsal claws. 14, 16. Fore wing. 15, 17. Hind wing. 4, 6, 8, 10, 13, 14, 15. ♀. 5, 7, 9, 11, 12, 16, 17. Ƌ.