Tachysphex loktionovi Mokrousov & Proshchalykin, 2021

Mokrousov, Mikhail V. & Proshchalykin, Maxim Yu., 2021, New and little-known digger wasps (Hymenoptera: Ampulicidae, Sphecidae Crabronidae) from Russia, Zootaxa 4952 (2), pp. 314-330 : 321-324

Tachysphex loktionovi Mokrousov & Proshchalykin , sp. nov.

( Figs 14–28 )

http://zoobank.org/NomenclaturalActs/

Diagnosis. The species belongs to T. pompiliformis species group and T. austriacus species complex (for recognizing see: Straka 2016). Complex includs T. austriacus Kohl, 1892 , T. pekingensis Tsuneki, 1971 , T. prismaticus Straka, 2005 , T. stysi Straka, 2008 , T. hungaricus Straka, 2016 , and T. smissenae Straka, 2016 . Females differ from all species (except T. austriacus ) by narrow vertex, WV:LV approximately 1.1 (in other species 1.2–1.4) and coloration—tibiae and hind femur completely or partly reddish (in T. stysi foretibia on inner surface and in T. pekingensis hind tibia partly reddish) and metasoma completely or predominantly red or red-brown (in other species metasoma red only at basal two or three segments, sometimes completely black); they also differ from T. stysi by denser punctation of scutum and scutellum ( Fig. 15 vs Fig. 36 ) and sparser than in other species, except T. austriacus ( Fig. 37 ); genae narrow (in other species, except T. austriacus , genae more robust). Tachysphex loktionovi sp. nov. differs from most morphologically related species T. austriacus by lighter coloration of legs and metasoma, more developed pubescence, more delicate sculpture of mesopleurae, as well as shape and sculpture of pygidium. Male (unknown in T. hungaricus ) differs by one tooth on inner margin of mandible (as in T. prismaticus and T. stysi ); mesopleural sculpture delicate, with distinguishable punctures (shagreened in other species); all tibiae usually more or less largely reddish (as in T. stysi ); medial lobe of clypeus nearly sinuate apically, with distinct lateral corners and without median emargination (in other species medial lobe of clypeus different or with median emargination); volsella sparsely setose, with about 15 setae on apical half (in other species about 18–20).

Description. Female ( Figs 14–21 ). Total body length 6.7–9.0 mm (holotype 8.0 mm); fore wing length of holotype 4.8 mm. Coloration very variable. In holotype mandibles mesally, palpi, tegulae, all tarsi, tibiae, hind femora, and metasoma ferruginous, partly with brownish darkeners; other parts black. In the darkest females ferruginous are mandibles (mesally), palpi, tegulae, tarsomeres, and outer surface (partly) of hind tibiae; metasoma predominantly ferruginous, darkened apically or largely brownish darkened.

Head ( Figs 16–18, 20 ). Head ratio H:W = 0.88; gena narrow, strongly converging behind compound eyes (dorsal view); vertex narrow, WV:LV = 1.07. Labrum flat, with nearly straight or widely emarginated medially anterior edge. Medial lobe of clypeus with irregular median emagination and deep lateral incisions; transition between clypeal basomedian area and bevel not sharp; basomedian area slightly convex, rather longer than bevel; bevel nearly flat, bright shiny, without or with one-three large punctures. Antenna relatively short; L:W F1, F2 and F3 = 2.4, 3.0 and 3.2 respectively. Frons and vertex distinctly punctate, punctures relatively large, less than one diameter apart, interspaces distinct and shiny; genae densely punctate, shiny; postocellar impression distinct but not deep, slightly transverse or rounded, not or slightly Y-shaped. Pubescence well developed, silvery, dense on face and genae, hiding sculpture on lower lateral parts of face; setae on vertex short, on lower part of genae about 1 × MOD, erect to semi erect.

Mesosoma ( Fig. 15 ). Scutal punctation irregular, punctures anteriorly and laterally less than one diameter apart; central part with punctures half to two or more diameters apart and shiny interspaces; scutellum sparsely punctate, punctures well developed and 1–2 diameter apart. Mesopleuron with cellular or squamous sculpture, interspaces shiny; ventral part densely punctate. Episternal sulcus ends far from mesopleural anterior edge. Pubescence well developed, silvery; setae on anterolateral part of mesonotum and posterolateral part of propodeum distinctly longer than MOD. Wings almost hyaline; veins brown; venation typical for genus. Legs: mid and hind trochanters ventrally with dense small punctures, sometimes mixed with a few slightly larger punctures, interspaces slightly shiny; punctures of fore trochanter minute, ill-defined and more dense; fore basitarsus with four preapical spines. Propodeal dorsum rugose, with more or less irregular longitudinal arcuate ridges; lateral and posterior parts with dense, but not coarse wrinkles.

Metasoma ( Fig. 19 ). TI–TIII with indistinct silvery apical bands. Tergal punctures ill-defined, from almost indistinguishable on TI, to more or less distinct on TV; apical depression of TV without punctures; TI–TV slightly shiny. Pygidial plate slightly longitudinally convex, elongate, sparsely punctate, shiny, interspaces with cellular microsculpture. Micropunctation of SII–SVI ill-defined; central part of SII–SV with distinct large punctures two to many diameters apart; interspaces slightly shiny.

Male ( Figs 22–28 ). Total body length 5.2–6.1 mm. Coloration: mandible (except base), palpi, tegula, forefemoral notch, all tarsi, tibiae, and two to four metasomal segments ferruginous or brownish; other parts black. Tibiae on one specimen almost completely black.

Head ( Figs 26, 28 ). Head ratio H:W = 0.9; genae narrow, strongly converging behind compound eyes (dorsal view); vertex wide, WV:LV = 1.66. Mandible with one distinct inner tooth. Labrum flat, arcuate. Medial lobe of clypeus without median emagination, nearly sinuate, with distinct lateral corners; clypeal basomedian area and bevel not separated with transition, clypeus (except medial lobe) uniformly weakly convex, bevel without micropunctation rather shorter than basomedian area (in one specimen large, reaches the basal third of the clypeus), with few large punctures. Antenna relatively short; L:W F1, F2 and F3 = 1.5, 2.1 and 2.5 respectively. Frons and vertex distinctly punctate, punctures relatively large, less than one diameter apart, interspaces distinct and shiny; genae unclearly micropunctate, shiny; postocellar impression distinct but not deep, slightly transverse or rounded. Pubescence much less developed than that of the female; setae shorter than MOD, erect or semi erect on vertex and genae.

Mesosoma ( Fig. 25 ). Scutal and scutellar punctation like in female, but punctures are slightly larger. Mesopleuron with smoothed sculpture, slightly shagreened dorsaly and posteriorly, with more distinct, but very flat punctures medially and anteriorly, interspaces shiny; ventral part with irregular punctuation, 1–2 diameter apart. Pubescence silvery, less developed than that of the female, mesonotal setae length about MOD, distinctly longer on mesopleuron and sides of propodeum. Legs: forefemoral notch not deep, distinctly larger than distance between notch and forefemoral base, central part of notch micropunctate, with distinct small setae, shiny ( Fig. 27 ); all trochanters with dense punctures, interspaces slightly shiny; tarsal rake not developed, but apical spines on outer side longer than on inner side. Sculpture of propodeum like in female, but more coarse.

Metasoma. TI–TIII with indistinct silvery apical bands. Tergal and sternal punctures ill-defined, interspaces slightly shiny. Penial valve as in Fig. 23 . Volsella ( Fig. 24 ) sparsely setose, with about 15 setae on apical half.

Type material (17 ♀, 7 ♂). Holotype — ♀, Russia: “ ТывА, оЗ. ТоРе-Холь // 27 км ЮЮЗ ЭРЗинА // 50.022°N, 95.041°E, // 11–12.VII.2014, Лелей, / ПРоЩАлыкин, Локтионов” (Tyva Republic, Tore-Khol’ Lake , 27 km SSW Erzin vill., 50.022°N 95.041°E, 11–12.VII 2014, Lelej, Proshchalykin, Loktionov) [ ZISP] ( Figs 14, 21 ) . Paratypes: with the same labels as holotype, 9 ♀, 1 ♂ [2 ♀, 1 ♂ in ZISP, 6 ♀ in MMC]; 2 ♂, 35 km SE Erzin, Tes-Khem Riv. , 50.010610°N 95.474605°Е, 5.VII.2013, MP, VL [ MMC]; 5 ♀, 1 ♂, 12 km SW Samagaltai vill., 50.518833°N 94.88665°E, 6–10.VII.2013 ( MP, VL); 1 ♀, 3 ♂, ibid., 17, 19.VII.2014, AL, MP, VL [ MMC]; 1 ♀, 25 km SE Erzin, Tes-Khem Riv. , 50.0798°N 95.352983°E, 14.VII.2014, AS, MP, VL [ MMC] . Other material (specimens in poor condition): with same label as holotype, 1 ♀ [ MMC]; 2 ♀, 12 km SW Samagaltai vill., 50.518833°N 94.88665°E, 6–10.VII.2013, MP, VL [ MMC] .

Etymology. The species is named after the well-known Russian entomologist, expert in Pompilidae (Hymenoptera) , one of the collectors of the type series, and our friend—V.M. Loktionov (Vladivostok, Russia).

Distribution. Tyva Republic ( Russia).

Figures

FIGURES 14–21. Tachysphex loktionovi sp. nov., holotype, female: 14—habitus, lateral view; 15— scutum and scutellum, posterodorsal view; 16–18—head, frontal view (16), lateral view (17), dorsal view (18); 19—pygidial plate; 20—clypeus; 21—labels. Scale bar: 2.0 mm.

FIGURES 22–28. Tachysphex loktionovi sp. nov., paratype, male: 22—habitus, lateral view; 23–24— genitalia, lateral view, apical part of penial valve (23), volsella (24); 25— meso-, metapleuron, and anterolateral part of propodeum, lateral view; 26—head, frontal view; 27—forefemur, ventral view; 28—clypeus. Scale bar: 2.0 mm.

FIGURES 35–37. Scutum, scutellum and metanotum of Tachysphex females: 35—T. mongolicus (from Tyva Rep.); 36—T. stysi Straka (from Uzbekistan); 37—T. austiacus Kohl (from Kazakhstan).