Palpostilpnus taynguyenensis Pham, Sheng, Park, Tran & Reshchikov, 2024

Pham, Nhi Thi, Sheng, Mao-Ling, Park, Clara, Tran, Duong Dinh & Reshchikov, Alexey, 2024, First record of the genus Palpostilpnus Aubert (Ichneumonidae: Phygadeuontinae) from Vietnam, with descriptions of eight new species, Zootaxa 5514 (6), pp. 525-549 : 545-547

Palpostilpnus taynguyenensis Pham, Sheng, Park, Tran & Reshchikov , sp. nov.

( Figures 2G , 14 )

Material examined. Holotype: ♀ ( IEBR), VIETNAM, Gia Lai Province, K’Bang district, Kon Chu Rang Nature Reserve , 14°29’57.4”N 108°34’22.1”E, 1,032 m a.s.l., 21 September 2023, sweep net, Dang T.H. coll. Antenna incomplete, with 22 flagellomeres remaining.

Diagnosis. Reddish yellow body with black markings; occipital carina dorsally broadly absent; postero-ocellar distance 0.6× ocular-ocellar distance; ventral side of F8 onwards of female flattened and thickened; combined area superomedia and area petiolaris of propodeum open anteriorly; area postero-externa incomplete; T1 1.5× as long as apical width.

Description of holotype. Face 1.4× as wide as high, granulose, with setae. Clypeal suture indistinct. Clypeus 1.6× as wide as high, moderately convex, coriaceous, ventral margin round. Mandible moderately stout, distinctly narrow to apex, teeth sharp, upper tooth slightly broader and longer than lower tooth. Malar space matt, equal to mandibular basal width ( Fig. 14A ). Gena subpolished, punctate, with setae. Frons and vertex with coarse punctures, posterior portion from behind ocelli to occipital carina vertical sloping. Postero-ocellar distance 0.6× ocular-ocellar distance, 0.8× as long as median ocellus diameter ( Fig. 14B ). Antenna with 22 flagellomeres remaining, ventral side of F8 onwards flattened and thickened. Occipital carina dorsally broadly absent ( Fig. 14B ).

Mesosoma. Pronotum punctate, with setae. Epomia absent ( Fig. 14D ). Mesoscutum granulate, 0.8× as long as its maximum width. Notaulus absent. Scutellum moderately convex, subpolished with fine punctures, except posteriorly smooth, lateral carina present basally ( Fig. 14C ). Mesopleuron punctate dorsally and ventrally, with setae, polished and impunctate medially; epicnemial carina present on ventral 0.6 of mesopleuron. Sternaulus shortly impressed behind epicnemial carina. Metapleuron subpolished, with punctures. Juxtacoxal carina absent ( Fig. 14D ). Propodeum steeply sloping in lateral view, dorsally subpolished with fine punctures. Lateromedian longitudinal carina present posteriorly, extending anteriorly shortly after meeting lateral part of posterior transverse carina. Combined area superomedia and area petiolaris open anteriorly.Area postero-externa incomplete ( Fig. 14E ). Spiracle small, circular.

Wings. Fore wing length 3.6 mm, vein 1cu-a strongly inclivous, interstitial to M&RS, postero-distal corner of subbasal cell ca. 70°, vein 3rs-m absent, vein 2rs-m about 1.5× length of M between 2rs-m and 2m-cu, length of CU between 1m-cu &M and 2cu-a 1.3× length of 2cu-a. Hind wing with distal abscissa of CU present, obsolescent near wing margin, length of CU between M and cu-a 3.0× length of cu-a.

Legs. Inner profile of basal portion of fore basitarsus distinctly bent. Hind coxa with distinct punctures. Hind femur 4.3× as long as its maximum width, slightly shorter than hind tibia length. Hind basitarsus 0.48× as long as tarsus.

Metasoma. T1 1.5× as long as apical width, polished, with punctures posteriorly, dorso-lateral carinae present; petiole flat; postpetiole broad; ventrolateral carina weak; spiracle small, round. T2 onwards densely punctate. T2 moderately long, 0.9× as long as basal width, 0.6× as long as apical width ( Fig. 14F ). Ovipositor thin, straight; ovipositor sheath 0.2× as long as hind tibia, 0.5× as long as hind basitarsus, enlarge apically ( Fig. 14G ).

Colour. Reddish yellow body. Head black, clypeus reddish, mandible (except apex) and palpi yellow. Dorsal part of scape, pedicel and F4–F9 white, of F1–F3 brown, of F10 onward black. Ventral view of F1–F4 entirely black, of F5–F7 white inner and black outer, flattened part of F8 onwards reddish brown. Hind tibia with basal and apical parts black. T1 reddish brown laterally and posteriorly, T2– T5 each with black band.

Male. Unknown.

Comparative notes. This new species resembles P. ngoclinhensis by the broad absence of the occipital carina dorsally, the shorter T1 and the open anteriorly of combined area superomedia and area petiolaris. It differs from the latter by the coloration and the sculptures of body.

Etymology. The species name refers to type locality, Gia Lai Province belongs to Tay Nguyen area (or the Central Highlands of Vietnam).

Distribution. Currently known only from evergreen forest at Kon Chu Rang Nature Reserve, Gia Lai Province, Vietnam.

Figures

FIGURE 14. Palpostilpnus taynguyenensis sp. nov., holotype female: A. head, frontal view; B. head, dorsal view; C. mesonotum; D. mesosoma, lateral view; E. propodeum; F. tergites; G. ovipositor (scale bar = 0.2 mm; G = 0.1 mm).

FIGURE2. Habitusof new species of Palpostilpnus fromVietnam:A.P.cattienensis sp. nov., holotypemale;B.P.hoanglienensis sp. nov., holotype female; C. P. melanothoracicus sp. nov., holotype male; D. P. incompletus sp. nov., holotype male; E. P. ngoclinhensis sp. nov., holotype male; F. P. melinhensis sp. nov., holotype female; G. P. taynguyenensis sp. nov., holotype female; H. P. meovacensis sp. nov., holotype female (scale bar = 1 mm).