Peristenus brunigaster, Ku & Samartsev & Belokobylskij, 2020

Ku, Deok-Seo, Samartsev, Konstantin G. & Belokobylskij, Sergey A., 2020, New species of Euphorinae parasitoids of the family Braconidae (Hymenoptera) from South Korea, Zootaxa 4742 (2), pp. 256-270 : 266-269

Peristenus brunigaster sp. nov.

Figs 7 , 8

Type material. Holotype: female, “ South Korea, Gyeongnam, Chinju-shi, Gajwadong, Malaise trap, 13–20.IV.1995, Deok-Seo Ku ” ( NIBR).

Paratypes. 1 female, Gyeonggido, Osan, Sucheongdong , Malaise trap, 21.IV.1999 (H.-G. Lee leg.) ( SMNE) ; 1 female, “ Korea, Gyeongnam Haman-gun, Daesan-myon, Jebi-san , Malaise trap (H type), 5–15.IV.1990 ” ( SMNE) .

Description. Female. Body length 2.8–2.9 mm; fore wing length 2.2–2.4 mm.

Width of head (dorsal view) 1.6–1.7 × its median length, 1.3–1.4 × width of mesoscutum. Head behind eyes (dorsal view) evenly roundly narrowed; transverse diameter of eye 1.2–1.3 × length of temple. Frons weakly concave, with distinct and complete median carina. Ocelli arranged in triangle with base 1.40–1.45 × its lateral sides; POL 2.5–2.7 × Od, 0.8–1.0 × OOL. Eye with sparse and rather long pale setae, 1.5 × as high as broad. Malar suture distinct. Malar space about equal to basal width of mandible, about 0.3 × height of eye. Face weakly convex, width of face 1.1–1.2 × its median height, 0.70–0.75 × height of eye. Distance between tentorial pits 2.8–3.2 × distance from pit to eye. Width of clypeus 2.3–2.5 × its median height, 1.0–1.1 × width of face. Head distinctly and almost linearly narrowed below eyes (front view). Occipital carina complete dorsally, fused with hypostomal carina ventrally.

Antenna weakly thickened, filiform, 23-segmented, 0.70–0.75 × as long as body. Scape 1.7–1.9 × longer than wide. First flagellar segment 3.3–3.5 × longer than its apical width, 1.25–1.30 × longer than second segment. Length of penultimate segment 1.2–1.3 × its width, 0.6–0.7 × length of apical segment, which is acuminate apically, but without spine.

Mesosoma. Length 1.5–1.6 × its maximum height. Notauli distinct, narrow, complete, crenulate. Prescutellar depression rather long, with high median carina, finely rugulose, 0.3–0.5 × as long as scutellum. Scutellum convex, with distinct transverse depression posteriorly. Subalar depression shallow, wide, punctate-rugose. Sternaulus shallow, rather wide, oblique, curved, rugulose-crenulate, without distinct furrow from posterior part of sternauli to hind coxa. Mesopleuron with finely sculptured oblique furrow going from mesopleural pit to sternauli.

Wings. Length of fore wing 3.0–3.3 × its width. Length of pterostigma 2.6–2.8 × its maximum width. Radial (marginal) cell shortened, 2.5 × longer than wide. Metacarpus (1-R1) 0.30–0.35 × as long as pterostigma, 0.8–1.0 × as long as width of pterostigma. Radial vein (r) arising distinctly behind middle of pterostigma, its second abscissa (3-SR + SR1) evenly curved. First radial abscissa (2-SR) very short. Recurrent vein (m-cu) distinctly antefurcal, 0.50–0.65 × as long as first radiomedial vein (2-SR). Discoidal (discal) cell petiolate anteriorly, 1.3–1.4 × longer than wide. Distance from nervulus (cu-a) to basal vein (1-M) 0.4–0.5 × nervulus (cu-a) length. Second abscissa of longitudinal anal vein (2-1A) shortly sclerotized basally. In hind wing, basal vein (1r-m) 1.0–1.1 × as long as second abscissa of mediocubital vein (1-M).

Legs. Hind femur evenly narrowed in posterior two-thirds, 4.3–4.6 × longer than its maximum width. Hind tarsus 0.9–1.0 × as long as hind tibia, its second segment 0.5 × as long as first segment, 1.2 × longer than fifth segment (without pretarsus). Fifth segment of fore and of middle legs weakly thickened. Claws thickened basally, with small tooth.

Metasoma. First tergite rather narrow basally, distinctly widened towards apex, without spiracular tubercles, with small dorsope. Apical width of first tergite 2.2–2.5 × its minimum width, length 1.4–1.6 × its apical width, 1.2 × longer than propodeum in lateral view. Length of second and third tergites combined 2.2–2.4 × basal width of second tergite, 1.3–1.5 × their maximum width. Ovipositor sheath very short, not projected behind tip of metasoma.

Sculpture and pubescence. Vertex in anterior half and temple sparsely and distinctly punctate with rugosity behind ocellar triangle, vertex finely punctate in posterior half; frons densely and coarsely punctate, with semicircular striation medially; face very densely and distinctly punctate; clypeus rugose-punctate. Mesoscutum mostly distinctly and densely punctate, its lateral lobes almost smooth postertiorly. Scutellum entirely densely punctate with rugosity. Mesopleuron mainly rugose, smooth only in medio-posterior parts. Propodeum coarsely rugulose-reticulate, with short semicircular punctulate or rugulose laterobasal areas. Hind coxa mainly smooth, but striate-rugulose basally. First metasomal tergite almost entirely regularly longitudinally striate. Median lobe of mesoscutum entirely and lateral lobes in apical two-thirds with dense short semi-erect setae, latero-posterior third of mesoscutum with sparse setae. Face with very dense white semi-erect setae. Clypeus almost entirely with rather long setae.

Colour. Body mainly black, metasoma behind first tergite light reddish-brown; clypeus reddish brown. Antenna entirely yellowish-brown or light reddish-brown, faintly infuscate towards apex. Palpi yellow. Legs light brown. Wings hyaline. Pterostigma brown, light brown in basal quarter.

Male. Unknown.

Comparative diagnosis. This new species is similar to Peristenus pacificus Belokobylskij, 1995 , but differs from it in having the temple shorter, with transverse diameter of eye 1.3 × length of temple (nearly equal in P. pacificus ), head behind eyes more strongly narrowed (less distinctly narrowed in P. pacificus ) and almost linearly narrowed below eyes (distinctly roundly narrowed in P. pacificus ), recurrent vein (m-cu) of fore wing rather strongly antefurcal (weakly antefurcal or interstitial in P. pacificus ), metacarpus (1-R1) shorter, 0.3 × as long as pterostigma (longer, about 0.4 × in P. pacificus ), second abscissa of radial vein (3-SR + SR1) evenly curved (almost straight in distal half in P. pacificus ), nervulus (cu-a) distinctly postfurcal (weakly postfurcal or almost interstitial in P. pacificus ), claws with small tooth (without tooth in P. pacificus ), scutellum densely punctate (with coarse irregular rugae and punctation in P. pacificus ), hind coxa dorsally mainly smooth (densely concentrically striate in P. pacificus ), antenna entirely yellowish-brown (mainly dark reddish-brown in P. pacificus ) and metasoma behind first tergite light reddish brown (almost black in P. pacificus ).

Etymology. This species is named from Latin “brunus” (brown) and “gaster” (abdomen) because of brown metasoma.

Figures

FIGURE 7. Peristenus brunigaster sp. nov. (female, holotype). A. Habitus, lateral view. B. Head, front view. C. Wings. D. Head, lateral view. E. Mesosoma, lateral view.

FIGURE 8. Peristenus brunigaster sp. nov. (female, holotype). A. Head and mesoscutum, dorsal view. B. Mesosoma, dorsal view. C. Propodeum, lateral view. D. Metasoma, lateral view. E. First and second metasomal tergites, dorsal view.