Pristaulacus tranganicus Long & Pham, 2024

Pham, Nhi Thi, Long, Khuat Dang, Dzuong, Nguyen Van, Mai, Pham Quynh & Turrisi, Giuseppe Fabrizio, 2024, The genus Pristaulacus Kieffer, 1900 (Hymenoptera: Aulacidae) in Vietnam and Northeastern Laos with descriptions of ten new species, Zootaxa 5432 (2), pp. 213-249 : 235-238

Pristaulacus tranganicus Long & Pham , sp. nov.

Figures 15–17, 23

Type material. VIETNAM: holotype, ♀, labelled “Aulac. 004 ” ( IEBR), N Vietnam: Ninh Binh, Trang An, Bai Dinh, forest, 20°16’9.9’’N 105°51’53’’E, 40 m, sweep, 24.vi.2017, Pham T.N. (IEBR) .

Etymology. Named after type locality, Trang An Scenic Landscape Complex, Northern Vietnam.

Diagnosis. Head from above 1.2 × wider than long; occipital carina moderately broad, lamelliform, interrupted medially, 0.7 × diameter of an ocellus; median occipital groove U-shaped ( Fig. 16A); pronotum, in lateral view, with one obtuse projecting tooth-like process; fore wing with vein 2-Rs+M short and discal cell more or less quadrate ( Fig. 17B); fore wing largely infuscate basally and medially, with large black substigmal spot; hind femur 0.8 × length of hind tibia; tarsal claws with four tooth-like processes; petiole elongate, gradually widened apically, 5.0 × its apical width; ovipositor 0.9 × fore wing length.

Description. (holotype, ♀), body length: 13.0 mm; antenna length: 5.3 mm; fore wing length: 10.5 mm; ovipositor length: 9.2 mm ( Fig. 15A).

Colour. Body largely black; scape dark brown; pedicel and flagellum black; mandible yellow basally, dark brown apically; fore wing largely infuscate basally and medially, with large black substigmal spot; wing veins and membrane pale brown; legs blackish brown to black, except tarsi pale brown to brown; ovipositor sheath brown; ovipositor yellowish-brown.

Head. From above 1.2 × wider than long; scape 1.6 × length pedicel; first flagellomere 1.7 × as long as scape, and 0.7 × length of second flagellomere; frons and clypeus densely punctate; frons and malar space with long pubescence ( Fig. 16B); malar space 0.4 × eye length; temple 1.2 × eye length dorsally; occipital carina interrupted along occipital medial groove; occipital medial groove U-shaped ( Fig. 16A); occipital carina lamelliform, 0.7 × diameter of an ocellus; POL: OOL = 8: 8; frons with dense fine punctures ( Fig. 16B); vertex and temple with sparse fine punctures ( Fig. 16C); distance between punctures 4.0 × puncture diameter.

Mesosoma . Propleuron rugulose ventrally, areolate-rugose medially and dorsally, with short pubescence, with one projecting tooth-like process anteriorly, and with tubercle protuberance posteriorly ( Fig. 17A); mesoscutum, in lateral view, distinctly protruding above pronotum; lateral lobes transversely rugose, with short setae ( Fig. 16D); scutellum transversely rugose; mesoprescutum and axilla areolate-rugose; metapostnotum wide, largely crenulate ( Fig. 16F); metapleuron and propodeum areolate-rugose; fore wing with veins 2-Rs and 1-Ma curved basally; r: 3-Rs = 16: 20; discal cell slightly narrowed anteriorly; 2-Rs+M very short, nearly quadrate, 2-Ma: 3-Ma: 3-Mb = 30: 9: 12 ( Fig. 17B); hind coxa moderately elongate ( Fig. 15B), transverse rugose dorsally, with long and sparse pubescence dorsally, subapical groove (ovipositor guide) deep, smooth, sparsely setose ( Fig. 15B); hind femur 0.8 × length of hind tibia; hind tibial spurs distinctly curved ( Fig. 16H); inner spur: outer spur = 12: 11; hind basitarsus 1.2 × length of tarsomeres 2–5 combined ( Fig. 16H); hind basitarsus 2.9 × length of second tarsomere; second tarsomere 2, 1.7 × length of third; third tarsomere 1.8 × length of fourth; fourth tarsomere 0.6 × length of fifth; third and fourth tarsus ventro-apically with long stout setae; tarsal claw with four robust tooth-like processes ( Fig. 16G).

Metasoma. Pyriform (lateral view) ( Fig. 17C), weakly compressed laterally; petiole elongate, gradually widened apically, 5.0 × its apical width ( Fig. 15A); tergite 2 mostly polished and shiny; remaining tergites with fine, superficial and dense punctures and short setae; ovipositor 0.9 × fore wing length.

Male. Unknown.

Taxonomic remarks. P. tranganicus , sp. nov. differs from P. dilleri Turrisi & Smith , from Laos, by the following characters: 1) Fore wing largely infuscate (vs fore wing hyaline with two small irregular brown spots in middle and one large substigmal brown spot in P. dilleri ); 2) Hind tarsus brownish (vs white yellowish in P. dilleri ); 3) 2-Rs+M short and discal cell more or less quadrate (vs 2-Rs+M long and discal cell elongate P. dilleri see Fig. 42 in Turrisi & Smith 2011); 4) Occipital groove U-shaped (vs V-shaped in P. dilleri , see Fig. 37 in Turrisi & Smith 2011); 5) Pronotum with posterior tubercle (vs posterior tubercle absent in P. dilleri ); 6) Petiole 5.0 × longer than wide (vs petiole very elongate in P. dilleri , 7.0 × longer than wide); 7) Ovipositor shorter than fore wing length (vs equal in P. dilleri ). The general appearance and the colour pattern resemble also P. comptipennis Enderlein, 1912 , widely distributed in the Southeastern Asia, but it is easily distinguished by the shape of the head with the temples very long and strongly narrowing behind eyes, shorter and weakly narrowing in P. comptipennis (see Fig. 19 in Turrisi & Smith, 2011), pronotum with posterior tubercle (absent in P. comptipennis ), and ovipositor shorter than fore wing (distinctly longer in P. comptipennis ).

Biology. Unknown.

Distribution. Northern Vietnam (Ninh Binh province) ( Fig. 23).