Pristaulacus mathematicus Turrisi & Jennings, 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 : 242-244

Pristaulacus mathematicus Turrisi & Jennings , sp. nov.

Figures 19, 20, 23

Type material. LAOS: holotype ♀, “ LAOS ( LAO), Prov. Houaphanh, Phou Pan (Mt.), Ban Saleui ( Village ), 20° 13’30’’N / 103°59’26’’E, 1350–1900 m MSL, 01.- 03.06.2009, leg. C. Holzschuh, and many locals”/ Pristaulacus mathematicus sp.n. ♀ Turrisi G.F. & Jennings J. T., Holotypus [red label]” ( OLML) .

Etymology. Named from the Latin “mathematicus ”, nominative form, meaning mathematics.

Diagnosis. Colour mostly blackish; wings hyaline; fore wing with a wide substigmal spot and base irregularly marked; fore and mid legs brownish to reddish orange, hind leg blackish with tarsus reddish orange; head shiny, punctures very fine, superficial and scattered, temples about eye width, convergent and weakly rounded posteriorly, occipital groove wide and deep, occipital carina moderately broad, lamelliform, 0.4 × diameter of ocellus, interrupted along groove; lateroventral margin of pronotum with a forwarded acute anterior tooth-like process, mesoscutum transverse-carinate, squared, slightly incavate medially; vein 2-Rs+M very short, indistinct; discal cell elongate ( Fig. 20F); vein 3-Ma slightly shorter than vein 3-Mb ( Fig. 20F); tarsal claws with four tooth-like processes; ovipositor 1.7 × fore wing length.

Description. (holotype, ♀), body length: 10.3 mm; antenna length: 9.4 mm; fore wing length: 8.1 mm; ovipositor length: 14.1 mm ( Fig. 19).

Colour. Colour almost entirely black, except: anterior margin of clypeus orange; mandible orange to dark reddish medially; A1 dark reddish dorsally, orange ventrally; fore wing with small and irregular dark marks on basal, discal 2 and subdiscal 1 cells, and a wide subquadrate substigmal brown spot ( Fig. 20F); tarsi orange (excluding pretarsi) ( Fig. 20G); wings hyaline; fore trochanter, fore and mid femurs and tibiae dark orange; setae goldish on mandible, whitish otherwise.

Head. From above 1.3 × wider than long dorsally, shiny ( Fig. 20A); vertex with fine to very fine, superficial and scattered punctures, distance between punctures 4.0–5.0 x puncture diameter; frons with fine, deep and moderately dense punctures, distance between punctures 1.5–2.0 × puncture diameter; clypeus with coarse, deep and dense punctures; gena with fine, superficial and scattered punctures, coarser and denser behind eye margin; malar area with moderately coarse, superficial and dense punctures very dense in the median-apical area; setae: erect and scattered on vertex ( Fig. 20B, C); erect and moderately dense on upper frons ( Fig. 20B); recumbent and dense on lower frons and clypeus ( Fig. 20B); semierect, moderately dense and moderately long on temple (length of setae 0.7 × diameter of anterior ocellus); recumbent and dense on malar area; malar space 0.3 × eye length; clypeus 3.0 × as wide as high; temple, from above, rounded and weakly convergent posteriorly, 0.8 × eye length; occipital margin weakly convex; occipital groove well developed, U-shaped, broad and deep ( Fig. 20A); occipital carina moderately broad, lamelliform, 0.4 × diameter of an ocellus, interrupted along medial occipital groove; POL: OOL = 9: 9 ( Fig. 20A); antenna 1.2 × fore wing length; scape broad, stout, 1.5 × length of pedicel; first flagellomere 1.6 × as long as scape, and 0.5 × length of second flagellomere.

Mesosoma . Pronotum, in lateral view, with one projecting very long acute tooth-like process ( Fig. 20E); propleuron polished, shiny, with very fine and scattered punctures and moderately long setae; mesoprescutum transverse-carinate, with 10 raised carinae, not elevated dorsally, only weakly convex ( Fig. 20D); mesonotum in dorsal view with weak median longitudinal impression and anterior margin weakly concave, lateral lobes not clearly defined ( Fig. 20D); in lateral view squared, not overhanging pronotum ( Fig. 20E); scutellum transverse carinate medially, areolate rugose on sides ( Fig. 20D); metapostnotum wide, largely crenulate ( Fig. 20D); propodeum areolate-rugose, with long and scattered setae; fore wing with vein 2-Ma straight; vein 2-Rs distinctly curved medially ( Fig. 20F); r: 3-RS = 7: 12; vein 2-Rs+M very short, indistinct, discal cell elongate; 2-Rs+M: 2-Ma: 3-Ma: 3-Mb = 0: 19: 4: 5 ( Fig. 20F); hind coxa slender, densely transverse carinate dorsally, polished punctate ventrally, setae long and sparse, subapical groove (ovipositor guide) wide and deep, with sparse setae ( Fig. 20H); apical trochanteral groove wide; trochantellus distinct; hind femur 0.7 × length of hind tibia; inner spur: outer spur = 10: 8; hind basitarsus 1.2 × length of tarsomeres 2–5 combined ( Fig. 20G); hind basitarsus 2.9 × second tarsomere length; second tarsomere 1.6 × length of third; third tarsomere 2.4 × length of fourth; fourth tarsomere 0.4 × length of fifth; tarsal claw with four robust tooth-like processes.

Metasoma. Pyriform (lateral view) ( Fig. 20I), sharply compressed laterally; petiole elongate, slightly widened apically, 4.0 × its apical width; petiole and tergite 2 polished and shiny; remaining tergites nearly coriaceous, with short and dense setae.

Male. Unknown.

Taxonomic remarks. The new species resembles at first glance a composite group of recently described species from Southeastern Asia due to the long or very long ovipositor (much longer than fore wing), including P. konishii Turrisi & Smith, 2011 , P. thailandensis Turrisi & Smith, 2011 , and P. watanabei Turrisi & Smith, 2011 . It is readily distinguished from P. konishii due to the wider occipital medial groove, 1.8 × wider than deep (narrower, 1.2 × wider than deep, in P. konishii ), and a shorter ovipositor, 1.7 × fore wing (very long in P. konishii , 2.5–2.7 × fore wing). It is readily distinguished from P. thailandensis due to the apex of fore wing not infuscate (distinctly infuscate in P. thailandensis ), hind tarsus reddish orange (dark brown in P. thailandensis ), upper margin of mesosoma weakly convex in lateral view, and anterior margin square (upper margin sharply convex, and anterior margin rounded in P. thailandensis , see Turrisi & Smith, 2011: Fig. 142), setae on sides of mesosoma moderately long and dense (long and very dense, partly obscuring sculpture in P. thailandensis ) and ovipositor longer 1.7 × fore wing length (shorter, 1.5 × fore wing length in P. thailandensis ).

This new species is distinguished from P. watanabei by the colour pattern, fore wing with only one substigmal brown spot, hind tarsus reddish orange, and metasoma almost entirely blackish (vs fore wing with large substigmal spot very extended posteriorly, two additional dark marks at base and apex slightly infuscate, hind tarsus blackish and metasoma extensively reddish orange in P. watanabei ), shape of the head with temples weakly convex and moderately convergent posteriorly (vs rounded and distinctly convergent posteriorly in P. watanabei , see Turrisi & Smith, 2011: Fig. 172), and ovipositor 1.7 × fore wing length (vs 1.5 × in P. watanabei ).

Biology. Unknown.

Distribution. Northeastern Laos (Houaphanh province) ( Fig. 23).