Probles (Euporizon) barycnemiformis, Khalaim, 2019

Khalaim, A. I., 2019, Four new species of the genus Probles Förster (Hymenoptera: Ichneumonidae: Tersilochinae) from Vietnam, Zoosystematica Rossica (China) 28 (1), pp. 120-131 : 121-124

Probles (Euporizon) barycnemiformis sp. nov.

( Figs 1–10)

Holotype. Female, Northwest Vietnam, Lai Châu Prov ., Hoang Lien National Park [Nature Reserve since 2006], 15 km W of Sa Pa, 1900 m, Malaise traps, 15–21.X.1999, coll. C. v. Achterberg ( RMNH).

Paratype. One female, same data as for holotype ( RMNH) .

Comparative diagnosis. The new species resembles the genus Barycnemis as it has a globose head with bases of antennae somewhat displaced downwards ( Fig. 5), mesosoma slightly compressed laterally, weakly curved foveate groove in centre of mesopleuron ( Fig. 8), and very long anterior part of propodeum ( Fig. 9), but other important features, e.g. slender legs, straight and slender spurs of hind tibia, and long and slender ovipositor ( Fig. 1) indicate that this is a species of the genus Probles . Probles barycnemiformis sp.nov. is easily distinguished from other Oriental and Palaearctic species of the subgenus Euporizon by the combination of long and strongly rounded genae ( Fig. 3) and exceptionally long anterior part of propodeum without distinct median longitudinal carinae ( Fig. 9). The new species also has a remarkably small clypeus ( Fig. 2).

Description. Female. Body length 3.2 mm, fore wing length 2.4 mm.

Head strongly rounded behind eyes in dorsal view ( Fig. 3), with bases of antennae somewhat displaced downwards ( Fig. 5); gena 0.85 times as long as eye width. Clypeus ( Fig. 2) small, lenticular, 3.0 times as broad as high and 0.8 times as broad as face (shortest distance between inner eye margins), almost flat, separated from face by thin and weak groove, predominantly smooth but shagreened near upper margin, very finely punctate in upper 0.4. Mandible moderately slender, distinctly tapered towards apex in basal half, with upper tooth somewhat longer than lower. Malar space 0.9 times as long as basal mandibular width. Antennal flagellum ( Fig. 5) filiform, with 17 flagellomeres; subbasal and mid flagellomeres 1.7–1.9 times and subapical flagellomeres about 1.6 times as long as broad; flagellomeres 3 to 5 with distinct and flagellomere 6 with weak subapical finger-shaped structures on outer surface ( Fig. 5). Face and frons granulate, dull, impunctate. Vertex granulate, dull, with very fine and sparse punctures. Gena smooth and shining centrally, very shallowly granulate in upper and lower parts, without distinct punctures. Occipital carina complete. Hypostomal carina absent ( Fig. 4).

Mesoscutum almost entirely granulate, dull and impunctate; mesopleuron centrally more or less smooth and with very fine, hardly discernible punctures. Notaulus weakly impressed, with indistinct irregular wrinkles on anterolateral side of mesoscutum. Scutellum with lateral carinae present only at extreme anterior in paratype and in anterior 0.3 in holotype. Foveate groove of mesopleuron weak and thin, slightly upcurved anteriorly, situated somewhat before centre of mesopleuron ( Figs 7, 8). Propodeum mediodorsally without distinct carinae; anterior part 1.15 times as long as apical area ( Fig. 9); apical area widely rounded anteriorly ( Fig. 9), flat; apical longitudinal carinae complete. Propodeal spiracle separated from pleural carina by 1.0–1.5 times diameter of spiracle ( Fig. 7).

Fore wing with second recurrent vein (2m-cu) distinctly postfurcal. Metacarpus (R1) not reaching tip of wing ( Fig. 6). First abscissa of radius (Rs+2r) straight, 1.4 times longer than width of pterostigma. Intercubitus (2rs-m) short and thick in holotype ( Fig. 6), but it weakly thickened and rather long (about as long as abscissa of cubitus between intercubitus and second recurrent vein = abscissa of M between 2rs-m and 2m-cu) in paratype. Hind wing with nervellus (cu1&cu-a) dis-

A.I. Khalaim. Four new species of Probles from Vietnam tinctly reclivous. Legs slender. Hind tibial spurs straight or slightly curved at apex. Tarsal claws not pectinate.

First metasomal tergite moderately slender, 3.7 times as long as posteriorly broad; petiole somewhat uneven dorsally and entirely striate laterally; postpetiole smooth ( Figs 7, 9). First tergite in lateral view with upper margin more or less straight in anterior 0.7 and strongly arcuate in posterior 0.3 ( Fig. 7); petiole trapeziform in cross-section; postpetiole in dorsal view somewhat broader than petiole. Glymma deep, moderately large, situated in centre of first tergite, joining by deep furrow to ventral part of postpetiole ( Fig. 7). Second tergite approximately 1.7 times as long as anteriorly broad. Thyridial depression clearly delimited, 2.5–3.0 times as long as broad. Ovipositor slender, weakly upcurved, with shallow dorsal subapical depression ( Fig. 10); sheath 2.6 times as long as first tergite.

Head, mesosoma and first metasomal segment black with slight brownish tinge; lower 0.5–0.6 of clypeus, mandible (teeth dark red) and mouthparts yellow. Antenna brown, but scape and pedicel ventrally yellowish. Pterostigma brown. Fore and mid legs brownish yellow, but mid coxa darkened with brown base, and fore and mid tibiae and tarsi slightly brownish. Hind leg with coxa and femur dark brown (femur pale basally and apically), trochanters brownish yellow (brownish dorsally in holotype), tibia and tarsus brownish yellow in paratype and yellowish brown in holotype (tibia pale at base). Metasoma behind first segment dark brown; posterior margins of tergites pale brown ( Fig. 1).

Male. Unknown.

Etymology. The species is named after the genus Barycnemis with the Latin suffix “-formis” (having the form of Barycnemis ).

Distribution. Northwest Vietnam.

Remark. The paratype female is partly destroyed, i.e. both antennae, both front legs and one mid leg are missing, and one fore wing is attached to the card point apart from the insect.