Sphictostethus arfak Loktionov & Lelej, 2018

Loktionov, Valery M. & Lelej, Arkady S., 2018, Discovery of the spider wasp genus Sphictostethus Kohl, 1884 (Hymenoptera: Pompilidae: Pepsinae) in New Guinea, with description of two new species, Zootaxa 4429 (2), pp. 295-302 : 298-300

Sphictostethus arfak Loktionov & Lelej , sp. nov.

( Figs 16–29 )

Material examined. Holotype, ♀, Indonesia, West Papua, 1190 m, Arfak Mts, Duebei env[irons], 20 km S Wamere, Manokwari distr. , 21.I–28.II.2008 (S. Jákl) [OLL].

Diagnosis. Female. Head in frontal view with vertex distinctly straight medially ( Fig. 16 ). Anterior margin of clypeus straight ( Fig. 16 ). Malar space well-developed ( Fig. 18 ). F1 3.5 times as long as maximum width. Mesopleuron with distinct conical tubercle posterolaterally ( Fig. 22 ). Propodeum with small tubercle dorsolaterally ( Figs 22, 24 ). T1 with long and narrow petiole anteriorly ( Fig. 24 ). Vein M of fore wing ending shortly beyond 3rsm vein and not continuous as a spectral vein ( Fig. 27 ). Head, mesosoma and legs mostly black. Male. Unknown.

Description. FEMALE. Length: body 11.9 mm; fore wing 11.2 mm. Head 1.05 times as wide as height; UID: MID: LID = 44: 55: 60; MID 0.5 times as long as head width; half of MID 1.0 times as long as eye width ( Fig. 16 ). Ocelli large, noticeably raised; ocellar triangle barely obtuse-angled; POD: OOD = 0.55 ( Fig. 19 ). Head in frontal view with vertex convex; vertex in frontal view distinctly straight medially ( Fig. 16 ); posterior margin of vertex in dorsal view barely concave medially ( Fig. 19 ). Frons on both sides of midline distinctly convex ( Fig. 16 ). Gena in dorsal view well-developed ( Fig. 19 ), in profile barely receding toward vertex ( Fig. 17 ). Malar space welldeveloped ( Fig. 18 ). Clypeus barely convex, 2.1 times as wide as length; anterolateral corner barely rounded; anterior margin straight ( Figs 16, 18 ). Mandible with stout subapical tooth. Flagellum filiform; ratio of scape, pedicel and F1–F4 30:12:33:30:42:43; F1 distinctly widening toward apex, 3.5 times as long as maximum width, and 0.75 times as long as UID; apical flagellomere pointed apically.

Mesosoma. In dorsal view subparallel, 2.2 times as long as maximum width. Pronotum conspicuously convex posterolaterally hence its posterior margin depressed laterally; posterior border deeply angulate ( Fig. 20 ). Discs of mesoscutum, mesoscutellum and metanotum convex. Metanotum medially 2.3 times as long as metapostnotum medially ( Fig. 24 ). Metapostnotum concave posteromedially; posterior margin arcuately emarginate. Mesopleuron with distinct conical tubercle posterolaterally ( Fig. 22 ). Propodeum evenly convex, with small tubercle dorsolaterally ( Figs 22, 24 ).

Legs. Protibia apically with four short stout spines on outer side and four smaller spines on inner side ( Fig. 26 ). Metatibia barely serrate dorsally ( Fig. 25 ). Longest spur of metatibia 0.47 times as long as metatarsomere 1. Metatarsomere 1 with scattered short spines dorsally and laterally (outside) and three rows of spines ventrally; metatarsomeres 2 and 3 with three rows of short spines ventrally; metatarsomere 4 with two shorter spines ventromedially; metatarsomere 5 without spines ventrally. Orbicula with 7–8 radiating long bristles; longest bristle 0.55 times as long as claw. Tarsal claws symmetrical with inner tooth larger than apical one ( Fig. 29 ).

Wings. Fore wing dark with two yellowish bands; vein M completely ending shortly beyond 3rs-m vein and not continuous as a spectral vein; venation as in Fig. 27 . Hind wing slightly infuscated with dark apical portion; venation as in Fig. 28 .

Metasoma. T1 anteriorly with long and narrow petiole ( Fig. 24 ). S2 with deep transverse arcuate groove medially.

Sculpture. Head and mesosoma matt; metasoma polished. Frons, discs of scutum and scutellum with denser fine punctures. Pronotum and disc of metanotum with finer punctures than on frons. Metapostnotum with fine transverse striae and narrow polished stripe along its posterior border. Propodeum with micropunctures anteriorly and posteriorly and fine transverse furrows medially. T1, T2 and S1 with scattered micropunctures. T3–T6 and S2– S6 with scattered fine pits. Antenna matt. Legs mostly matt with femur somewhat polished ventrally.

Colour. Body mostly black; frons and gena along orbit, clypeus, pedicel and scape somewhat orange brown; pronotum with inconspicuous reddish brown spots dorsolaterally; propleuron barely orange brown ventrally; mesopleuron posteroventrally and legs somewhat reddish brown; T2 with large orange brown spot on each side anterolaterally ( Fig. 23 ); S2 orange brown anteriorly.

Pubescence. Body without setae except following: upper frons with one long and two shorter pale erect setae along orbit; anterior portion of clypeus with few pale setae; anterior margin of labrum with denser very short stout bristles ventrally; mandible with few short pale setae; prementum with fascicle of five very long thin and barely curved in upper half pale bristles ( Fig. 21 ); propleuron and procoxa with scattered pale setae; discs of scutum and scutellum with few pale setae; propodeum with short silver setae posterolaterally; S1 with short scattered setae; S2–S6 and T6 with long setae. Frons with golden brown micropubescence. Clypeus with silver micropubescence. Pronotum laterally, pro- and mesopleuron, coxae anteriorly, propodeum posterolaterally with whitish pubescence. Metasoma without pubescence.

MALE. Unknown.

Comparison. The female of this new species is similar to that of Sphictostethus yidyam Krogmann & Austin, 2011 from Australia in having the propodeum with a tubercle dorsolaterally ( Fig. 22 ), the protibia without a distinct elongate stout spine dorsoapically ( Fig. 26 ), and the fore wing dark with light bands ( Fig. 27 ), but it can be easily distinguished by the following traits: head in frontal view with the vertex straight medially ( Fig. 16 ) vs evenly arcuate medially in S. yidyam ; anterior margin of clypeus straight ( Fig. 16 ) vs barely bisinuate in S. yidyam ; malar space well-developed ( Fig. 18 ) vs not developed in S. yidyam ; F1 3.5 times as long as maximum width vs 4.47– 4.79 times in S. yidyam ; vein M of fore wing ending shortly beyond 3rs-m vein and not continuous as a spectral vein ( Fig. 27 ) vs reaching wing margin as a hardly visible relict spectral vein in S. yidyam ; and head, mesosoma, and legs mostly black vs dark purple in S. yidyam .

Distribution. New Guinea: Indonesia (West Papua).

Etymology. The new species is named after the indigenous people living in West Papua and also refers to Mts. Arfak, the type locality of the species. The specific epithet is to be treated as a noun in apposition.

Figures

FIGURES 16–29. Sphictostethus arfak sp. nov., ♀, holotype. 16. Head, frontal view. 17. Head, lateral view. 18. Clypeus, dorsolateral view. 19. Head, dorsal view. 20. Pronotum and scutum, dorsal view. 21. Head ventrally, lateral view. 22. Mesosoma, dorsolateral view. 23. Metasoma, dorsal view. 24. Scutellum, metanotum, metapostnotum, propodeum and T1, dorsal view. 25. Metatibia, lateral view. 26. Protibia, dorsal view. 27. Fore wing. 28. Hind wing. 29. Metaclaw. Scale bar for 16–28 = 0.5 mm, for 29 = 0.1 mm.