Palpostilpnus incompletus 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 : 530-531

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

( Figures 2D , 6 )

Material examined. Holotype: ♂ ( IEBR), VIETNAM, Vinh Phuc Province, Me Linh Biodiversity Station for Biodiversity , 21°23’03”N 105°42’40’E, 70 m a.s.l., 1–10 June 2020, Malaise trap, Tran D.D. coll.

Diagnosis. Ferruginous body with black markings; occipital carina dorsally broadly absent; postero-ocellar distance 1.5× ocular-ocellar distance; combined area superomedia and area petiolaris of propodeum closed; T1 stout, 1.5× as long as apical width.

Description of holotype. Face 1.2× as wide as high, puncto-striate, with dense setae, centrally weakly convex. Clypeal suture indistinct. Clypeus 1.8× as wide as high, weakly convex, similar sculptures as face, ventral margin round. Mandible moderately stout, gradually narrowed to apex, teeth sharp, upper tooth much broader and slightly longer than lower tooth. Malar space matt, equal to mandibular basal width ( Fig.6A ). Gena punctate, with setae.Frons and vertex coarsely punctate, posterior portion from behind ocelli to occipital carina steeply sloping. Postero-ocellar distance 1.5× ocular-ocellar distance, equal to median ocellus diameter ( Fig. 6B ). Antenna with 23 flagellomeres. Occipital carina dorsally broadly absent ( Fig. 6C ).

Mesosoma. Pronotum polished with sparse punctures dorsally. Epomia present ( Fig. 6E ). Mesoscutum granulate, 1.0× as long as its maximum width. Notaulus absent. Scutellum moderately convex, densely finely punctate, except narrowly polished and impunctate posteriorly, lateral carina present basally ( Fig. 6F ). Mesopleuron polished, punctate, with setae, except medially impunctate; epicnemial carina present on ventral 0.7 of mesopleuron. Sternaulus shortly impressed behind epicnemial carina. Metapleuron densely punctate, with setae. Juxtacoxal carina present anteriorly ( Fig. 6E ). Propodeum gradually sloping in lateral view with moderately dense punctures dorsally and laterally. Combined area superomedia and area petiolaris closed, with sparse punctures ( Fig. 6G ). Spiracle small, circular.

Wings. Fore wing length 2.7 mm, vein 1cu-a interstitial to M&RS, inclivous, postero-distal corner of subbasal cell ca. 70°, vein 3rs-m absent, vein 2rs-m about 1.4× length of M between 2rs-m and 2m-cu, length of CU between 1m-cu&M and 2cu-a 1.4× length of 2cu-a. Hind wing with distal abscissa of CU present, obsolescent near wing margin, length of CU between M and cu-a 5.0× length of cu-a.

Legs. Inner profile of basal portion of fore basitarsus distinctly bent. Hind coxa with indistinct punctures. Hind femur 4.0× as long as its maximum width, 0.9× as long as hind tibia length. Hind basitarsus 0.45× as long as tarsus.

Metasoma. T1 1.5× as long as apical width, polished, with dense punctures posteriorly, dorso-lateral carinae present; petiole flat; postpetiole broad; ventrolateral carina weak; spiracle small, circular. T2 onwards densely punctate, with setae. T2 broad posteriorly, 1.2× as long as basal width, 0.7× as long as apical width ( Fig. 6D ).

Colour. Ferruginous with black markings. Head black, mandible (except apex), palpi, scape, pedicel and F1–F2 yellow, ventral part of F3 onwards yellowish brown. Fore and mid legs yellow. Hind leg reddish yellow with basal and apical parts of tibia black.

Female. Unknown.

Comparative notes. This new species resembles P. pterodactylus by the broad absence of the occipital carina dorsally and the shorter of T1. It differs from the latter by the coloration of body and by its elongate mesoscutum (1.0× as long as its maximum width vs. 0.85×).

Etymology. The species name derived from Latin “incompletus ” refers to the occipital carina broadly absent dorsally.

Distribution. Currently known only from secondary lowland forest at Me Linh Station for Biodiversity, Vinh Phuc Province, Vietnam.

Figures

FIGURE 6. Palpostilpnus incompletus sp. nov., holotype male: A. head, frontal view; B. head, dorsal view; C. head, posterior view; D. tergites; E. mesosoma, lateral view; F. mesonotum; G. propodeum (scale bar = 0.2 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).