Palpostilpnus angkor, Reshchikov & Santos & Liu & Barthélémy, 2019

Reshchikov, Alexey, Santos, Bernardo F., Liu, Jing-Xian & Barthélémy, Christophe, 2019, Review of Palpostilpnus Aubert (Hymenoptera, Ichneumonidae, Phygadeuontinae), with the description of ten new species, European Journal of Taxonomy 582, pp. 1-63 : 40-43

Palpostilpnus angkor sp. nov.

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Fig. 22

Diagnosis

Body short and stout, mostly pale yellow and black ( Fig. 22A ); T2–T5 with distinct sub-apical transverse black stripes; antenna distinctly shorter than body, medially strongly flattened; postero-ocellar distance 3.4 times ocular-ocellar distance; mesoscutum moderately long, 0.9 times as long as broad ( Fig. 22E ), distinctly convex, anteriorly slightly projecting over pronotum; propodeal carinae absent except for vestiges of posterior transverse carina and posterior portion of median longitudinal carina; wings hyaline ( Fig. 22A ); T1 1.7 times as long as apically broad ( Fig. 22D ). Ovipositor 0.27 times as long as hind basitarsus.

Etymology

The specific name is derived from the type locality, Angkor Wat.

Material examined

Holotype CAMBODIA • ♀; Siem Reap Province, Angkor, Praeh Khan Temple ; Malaise trap; 24 Jan.–21 Feb. 2006; Oul Yothin leg.; RBINS.

Paratype BRUNEI • 3 ♀♀; Labi; 200 m a.s.l.; mixed dipterocarp forest; Aug–Sep. 1979; I. Gauld leg.; NHMUK .

Description

Female SIZE. Fore wing length 3.3 mm. Body short and stout, 1.50 times as long as high.

HEAD. Face 1.4 times as broad as high, centrally slightly convex, alutaceous ( Fig. 22B ). Clypeal suture indistinct, but clypeus distinctly delimited by change of sculpturing. Clypeus slightly convex, shiny, distinctly striated, with sharp, truncate apical margin. Basal portion of mandible smooth; dorsal tooth lanceolate, broader than ventral tooth. Malar space alutaceous, 1.3 times as long as basal mandible width. Gena glossy, mostly smooth with sparse shallow punctures, dorsally forming weak carina posterior to dorsal corner of eye and with angled, carina-like elevation between lateral ocellus and occipital carina. Vertex ( Fig. 22E ) sparsely punctate, posterior portion from behind ocelli to occipital carina slanted almost vertically, slightly concave. Postero-ocellar distance 3.4 times ocular-ocellar distance. Frons coriarious-punctate, lower portion not distinctly concave. Antenna distinctly shorter than body, with 25 flagellomeres, median portion strongly thickened. Occipital carina complete.

MESOSOMA. Pronotum punctate-areolate ( Fig. 22C ). Epomia indistinct. Mesoscutum ( Fig. 22E ) moderately long, as long as broad, distinctly convex, anteriorly slightly projecting over pronotum, with granulated texture and large shallow punctures. Notaulus indistinct. Scutellum flat, elongate, with fine sparse punctures. Postscutellum punctate. Mesopleuron ( Fig. 22C ) centrally smooth, shiny, distinctly punctate on its margins. Epicnemial carina reaching dorsal 0.6 of mesopleuron. Sternaulus distinct on anterior 0.8 of mesopleuron. Metapleuron long and narrow, shallowly punctate-areolate. Juxtacoxal carina short but distinct. Submetapleural carina complete. Fore wing with 1cu-a distinctly distad of M becoming Rs, 3rs-m absent, distal abscissa of M spectral; ramulus absent; length of vein Cu slightly longer than 2cu-a. Hind wing with cu-a strongly inclivous and interrupted at lower 0.18. Distal abscissa of Cu spectral. Distal abscissa of M spectral. Inner profile of basal portion of fore basitarsus distinctly bent. Hind coxa anteriorly shallowly punctate, posteriorly smooth. Propodeum steeply sloping in lateral view ( Fig. 22C ), mostly covered by dense shallow punctures, posterocentrally smoother. Propodeal carinae absent ( Fig. 22D ).

METASOMA. T1 1.7 times as long as apically broad, petiole dorsally flat and smooth, laterally punctate; postpetiole slightly convex, moderately broad; with sparse, distinct punctures, dorsolateral carina complete and strong until spiracle; ventrolateral carina complete but anteriorly weak; spiracle small, round, not prominent. T2–T5 coarsely and sparsely punctate; T2 widened posteriorly, almost apically wide. Ovipositor 1.7 times as long as hind basitarsus.

COLOUR. Mostly yellowish and black. Head black; basal 0.8 of mandible, scape and ventral face of pedicel pale yellow; mandible apex, dorsal face of pedicel and basal flagellomeres ferruginous, flagellum gradually changing to dark brown by fifth flagellomere. Pronotum, propleuron, posterior 0.7 of mesoscutum, axillary trough, most of mesopleuron, mesosternum and about 0.9 of propodeum black. Anterior arc on mesoscutum, scutellum, ovoid spot on anterior corner of mesopleuron, metapleuron and two small sublateral spots on posterior end of propodeum pale yellow. Fore and mid legs pale yellow, gradually darker towards apex. Hind coxa extensively black on mesal face; trochanter black; trochantellus and femur ferruginous, with small black marks; hind tibia basally pale yellow, gradually changing to ferruginous and black towards apex; hind tarsus pale yellow except for black T5. Wings hyaline. Pterostigma and veins yellowish brown. Metasoma mostly pale yellow or light ferruginous; T1 dorsally with transverse black stripe opposite spiracle, area immediately adjacent to stripe ferruginous; T2–T5 with distinct sub-apical transverse black stripes; T6 and T7 laterally ferruginous, T8 almost entirely ferruginous. Ovipositor sheath basally pale yellow, apically brown.

Male

Unknown.

Variation

Fore wing 3.1–3.5 mm long. Antenna with 23–25 flagellomeres. Dorsoposterior corner of pronotum sometimes with small yellowish mark; anterior pale yellow arc on mesoscutum sometimes medially interrupted; pale yellow mark on mesopleuron sometimes restricted to subalar ridge; punctures on mesopleuron restricted to its margin to variously invading the central, otherwise smooth, area; black areas in propodeum covering 0.2–0.9 of its area; black marks on hind coxa and trochanter sometimes reduced; black stripe on T2 sometimes incomplete; marks on T3 and T4 variable in size, sometimes distinct as clear circular spots, sometimes almost indistinct.

Remarks

Very similar to P. maculatus Sheng & Sun, 2013 , from which it can be differentiated mainly by the following characters: mesoscutum longer (as long as broad) and distinctly convex, anterior margin projecting over pronotum (vs 0.75 times as long as broad in P. maculatus , and flat, not projecting over pronotum); T1–T5 all with distinct black stripes (vs distinct stripes only at T1 and T2, while T3 and T4 with small sublateral marks); antenna shorter and stouter; postero-ocellar distance distinctly much longer (3.4 times vs 2.3 times ocular-ocellar distance).

Distribution

Brunei, Cambodia.

Figures

Fig. 22. Palpostilpnus angkor sp. nov., holotype, ♀ (RBINS). A. Lateral habitus. B. Head, anterior view. C. Mesopleuron. D. Propodeum and T1, dorsal view. E. Scutum.