Tachysphex stysi, Straka, 2008

Straka, Jakub, 2008, Tachysphex stysi sp. nov. (Hymenoptera: Apoidea: Crabronidae) from Central Asia, Acta Entomologica Musei Nationalis Pragae 48 (2), pp. 691-696 : 692-695

Tachysphex stysi sp. nov.

( Figs. 1-7 )

Type material. HOLOTYPE: KAZAKHSTAN, J, ‘ Kasachstan mer. / Chagir 42,2N, 68,8E / 40 km S Aris / leg K. Denes 6.5.94’ [printed label] ( OLML) . PARATYPES: KAZAKHSTAN: same locality and date as holotype, 67 JJ 28 ♀♀, K. Deneš, J. Halada, Ma. Halada and J. Kadlec lgt .; Djambul 10 km E, 31.v.1994, 2 ♀♀, J. and Ma. Halada lgt . TAJIKISTAN: Aruk-Tau , Garavuti, 20.iv.1978, 1 ♀, J. Niedl lgt . TURKMENISTAN: Sandikatzi env., 3.-13.v.1993, 12 ♀♀, K. Deneš, J. Halada and Mi. Halada lgt .; Nebit-Dag , 1.v.1993, 1 ♀, Mi. Halada lgt. (all specimens in OLML and JSPC) .

Description. Male (holotype). Body length: 7.5 mm.

Coloration. Apical half of mandible, tegula, metasomal segments I and II, all bases of femora, tibiae and all tarsi red. Other body parts all black.

Head. Inner margin of mandible circularly emarginate, with one well developed tooth ( Fig. 1 ). Labrum flat, not emarginated. Clypeus slightly convex; basomedian area slightly convex, densely punctate; bevel abrupt, as long as one third of clypeus, shiny ( Fig. 1 ); lip arcuate, with median emargination and distinct lateral corners. Antennae short. Frons and vertex densely and uniformly punctate, punctures minute, most punctures less than one diameter apart, interspaces slightly shiny; setae shorter than MOD, erect to semierect.

Mesosoma. Scutum densely but variably punctate, punctures less than half to one and half diameter apart, scutellum uniformly punctate, punctures about one diameter apart, all interspaces distinctly microsculptured, shiny. Mesopleuron finely rugose; its lower part with poorly defined punctation, punctures evanescent in microsculpture and rugosity, less than one diameter apart. Mesothoracic venter densely punctate, punctures ill-defined, about half diameter apart. Propodeal dorsum with conspicuous irregular longitudinal ridges, interspaces strongly sculptured to rugose, dull. Propodeal side obliquely ridged. Venter of all trochanters finely micropunctate, punctures no more than one diameter apart, interspaces shiny. Fore femoral notch semicircular, sparsely setose and with shiny surface ( Fig. 2 ). Wings nearly hyaline; veins brown.

Metasoma. Terga I-IV with weak, but distinct silvery apical bands; apical depressions on all terga slightly translucent, barely defined. Terga (including apical depressions) densely micropunctate, punctures ill-defined, evanescent in microsculpture. All sterna with uniform sculpture similar to that on terga, but punctures more distinct. Gonostyle with about 20 setae on apical half; setae uniform in length or nearly so. Volsella similar to that of T. prismaticus Straka, 2005 in shape (cf. Fig. 13 in STRAKA (2005)); setae on volsella uniformly or nearly so directed ventrally ( Fig. 3 ).

Variation in males. Body length: 5.5-7.5 mm. Head. Clypeal lip with or without median emargination; WML: LCL = 0.8-0.9; WCL: WML = 2.4-2.6.Antennae relatively short; LF1: WF1 = 1.7-1.8; LF3: WF3 = 1.8-1.9. Frons and vertex densely, uniformly punctate, punctures one to less than one diameter apart, interspaces shiny to slightly dull; WV: LV = 1.2-1.3.

Female (general description). Body length: 7.0- 9.5 mm.

Coloration. Mandible mesally, two or three distal tarsomeres, and gastral segments I-II or I-III red. Tegula reddish translucent. Other body parts all black.

Head. Labrum flat, slightly emarginated medially. Clypeal lip with deep irregular median emargination ( Figs. 5-6 ); transition between clypeal basomedian area and bevel relatively sharp, angulated; basomedian area convex, about as long as bevel; bevel concave, bright shiny; WML: LCL = 1.5-1.6, WCL: WML = 1.9. Antenna relatively short; LF1: WF1 = 3.0-3.1; LF3: WF3 = 3.0-3.1. Frons and vertex uniformly punctate, punctures less than one diameter apart, more than that on vertex, interspaces microsculptured, slightly shiny to dull ( Fig. 7 ); setae short, erect to nearly erect; postocellar impression distinct and deep, obtusely Y-shaped; WV: LV = 1.1-1.3 ( Fig. 7 ). Malar space and adjacent part of gena almost impunctate, integument bright and shiny; gena densely punctate.

Mesosoma. Scutum and scutellum unevenly punctate. Central part of scutum sparsely punctate except for middle line, punctures one to many diameters apart; all margins and middle line densely punctate, punctures at most one diameter apart; all interspaces sparsely micropunctate, microsculptured and shiny. Scutellum more densely punctate in the middle than on sides, punctures variable in size and intermixed with micropunctation, half to two diameters apart, interspaces slightly microsculptured to unsculptured, shiny. Mesopleuron (including hypoepimeral area) finely, uniformly rugose throughout. Mesothoracic venter densely punctate. Propodeal dorsum uniformly rugose, in most specimens with more or less irregular longitudinal ridges. Propodeal side obliquely ridged, ridges conspicuous in most specimens. Venter of mid and hind trochanters with large punctures several diameters apart, interspaces shiny; punctures of fore trochanter minute, ill-defined, interspaces microsculptured, dull. Fore basitarsal rake with five preapical spines and one subapical ( Fig. 4 ). Wings almost hyaline to slightly darkened at apex; veins brown.

Metasoma. Terga I-IV with indistinct silvery apical bands; apical part of terga I-III slightly translucent. Tergal punctures minute, ill-defined, evanescent in fine microsculpture; apical depressions without distinct punctures; all terga dull. Nearly entire sternum II with well defined micropunctures, micropunctation of other sterna ill-defined, present only on sides; central part of all sterna with distinct large punctures that are two to many diameters apart; interspaces slightly shiny to dull. Pygidial plate slightly convex, superficially looking flat; sparsely punctate, interspaces not sculptured and shiny.

Differential diagnosis. Tachysphex stysi sp. nov. is a member of the T. pompiliformis species group and the T. austriacus species subgroup. It resembles other members of the subgroup: T. austriacus , T. pekingensis Tsuneki, 1971 , T. prismaticus Straka, 2005 and at least three other undescribed central Asian species (J. Straka, unpublished data) in having the characters of the subgroup (see above). It differs from these species in the following combination of characters. Male: inner margin of mandibles circularly emarginated with one well developed tooth ( Fig. 1 ); mid trochanters ventrally distinctly and uniformly punctate; four metasomal terga with short silver apical bands (visible in fresh specimens); all tibiae largely and all bases of femora red. Female: scutum variably punctate, punctures half to one diameter apart in anterior parts, in the middle and along all margins, mesolaterally with large interspaces among punctures, punctures up to five diameters apart; mid and hind trochanters ventrally sparsely punctate, punctures large, several diameters apart; fore basitarsal rake usually with five apical spines ( Fig. 4 ); at least inner surface of fore tibia red, mid and hind tibiae black.

Males of T. prismaticus possess a similar shape of the mandibles as in male T. stysi sp. nov. (one tooth). However, both male and female of T. prismaticus differ from the new species by the black legs and moreover female T. prismaticus differ in the sculpture of the scutum, which is densely and uniformly punctate. Tachysphex austriacus and T. pekingensis are quite similar to each other. Both species possess two teeth on the inner margin of male mandibles, a uniformly sculptured scutum in females, and a densely punctate ventral part of all trochanters in both sexes. The tibiae are (at least partly) red in T. pekingensis but black in T. austriacus . Finally, males as well as females of the undescribed species are all black and males possess no distinct tooth on the inner margin of the mandibles. These species differ strongly from other species in body sculpture and vestiture.

Name derivation. Named in honour of the excellent Czech entomologist Professor Pavel Štys (Charles University, Prague).

Distribution. Kazakhstan, Tajikistan, Turkmenistan.

Figures

Figs. 1-7. Tachysphex stysi sp. nov. 1-3 – male: 1 – clypeus and mandibles; 2 – forefemoral notch, ventral view; 3 – volsella, outer view. 4-7 – female: 4 – foretarsomeres with rake; 5 – clypeus and mandibles; 6 – clypeus, detail; 7 – vertex.