Wilkinsonellus carinatus Liu & Polaszek 2025, sp. nov.

Wilkinsonellus carinatus Liu & Polaszek sp. nov. Fig. 3 Diagnosis. Body 2.7 mm long, black, except T 1, lateral part of T 2 – T 7 light brown (Fig. 3 a); OOL: OD = 1.7 (Fig. 3 b); face with minute punctures, their intervals uneven to transversely rugulose (Fig. 3 c); antenna 1.3 × as long as body length, with penultimate flagellomere 2.6 × as long as wide (Fig. 3 d); mesoscutum distinctly strigose with a medio-longitudinal carina posteriorly; scutellum with dense umbilicate punctation, protruding far above level of propodeum in lateral view (Fig. 3 e); propodeum areolate-rugose along inner side of oblique carinae (Fig. 3 i); mesopleuron largely smooth except densely punctate on anterior and upper edges (Fig. 3 f); vein r 0.8 × 2 - SR (Fig. 3 g); metacoxa extending nearly to apex of metasoma, with areolate-rugose sculpture on outer dorsal edge, nearly smooth medio-longitudinally, finely punctate ventrally (Fig. 3 f); petiole of T 1 smooth, 2.0 × as long as basal width, 4.4 × as long as medial width; T 2 subtriangular, smooth, 1.8 × as wide as length in the middle; T 3 about as long as T 2 (Fig. 3 l); hypopygium broad (Fig. 3 k). Description. Female. Body length 2.7 mm, fore wing length 3.2 mm (Fig. 3 a). Head. 1.7 × as wide as long, 0.8 × as wide as mesoscutum. Eyes 1.7 × longer than temple in dorsal view. Temple dull with small punctures, rounded behind eyes in dorsal view. Vertex dull with small sparse punctures, slightly transversely rugulose behind ocelli. Ocelli large, distance between fore and a posterior ocellus 0.6 × as long as minor axis of a posterior ocellus, POL: OD: OOL = 1.0: 1.0: 1.7. Frons slightly depressed, with curved carinae around sockets (Fig. 3 b). Face slightly shiny with minute punctures, their intervals uneven to transversely rugulose, slightly bulging medio-longitudinally, 0.9 × as wide as high. Clypeus 2.3 × as wide as medial length, nearly smooth with superficial punctures. Length of malar space 1.4 × width of mandible (Fig. 3 c). Antenna 1.3 × as long as body length, with 1 st, 2 nd and penultimate flagellomeres 3.3, 3.1, and 2.6 × as long as wide, 1 st indistinctly longer than 2 nd, flagellomeres gradually shortening towards penultimate flagellomere, closely articulated (Fig. 3 d). Mesosoma. Length: width: height = 1.1: 1.0: 1.1. Mesoscutum dull with even punctures, which tend to be larger along the “ imaginary ” notauli, intervals uneven with minute punctuation and about the length of a puncture’s diameter, and distinctly strigose with a medio-longitudinal carina posteriorly. Scutellar sulcus wide and straight with carinae inside. Scutellum dull with dense umbilicate punctation, medial part of posterior band of scutellum rough, protruding far above level of propodeum in lateral view (Fig. 3 e, f). Propodeum 2.8 × wider than high, dull with a strong percurrent medio-longitudinal carina, and adjacent oblique carinae, which have weak transverse carinae between them, shallowly punctate anterio-laterally, areolate-rugose along inner side of oblique carinae; spiracles large, enclosed by costulae (Fig. 3 i). Mesopleuron shiny, largely smooth except densely punctate on anterior and upper edges, sternaulus crenulate, with an oblique furrow attaching right-angled to its anterior end (Fig. 3 f). Wings. Fore wing: pterostigma narrow, 3.4 × as long as its widest part; vein 1 - R 1 1.4 × length of pterostigma; vein r arising from apical third of pterostigma, slightly longer than maximum width of pterostigma, 0.8 × 2 - SR; vein m-cu 2.3 × as long as 2 - SR + M, nearly as long as 2 - SR; vein 1 - CU 1 0.7 × 2 - CU 1 and 1.7 × cu-a (Fig. 3 g). Hind wing: vannal lobe of normal size, posterior margin with short setae medially, basally and apically with longer setae, cu-a slightly curved (Fig. 3 h). Legs. Metacoxa long, extending nearly apex of metasoma, areolate-rugose sculptures on outer dorsal edge, nearly smooth medio-longitudinally, finely punctate ventrally (Fig. 3 f). Metafemur 3.4 × as long as its widest part. Inner spur of metatibia 4 / 5 length of metabasitarsus. Metabasitarsus 0.7 × as long as combined length of tarsomeres 2–5 (Fig. 3 j). Metasoma. 0.9 × length of mesosoma. Petiole of T 1 smooth, bottle-shaped, attenuated to posterior edge, 2.0 × longer than basal width, 4.4 × longer than medial width, petiole with a groove reaching to half of apical swollen area. T 2 subtriangular, smooth, 1.8 × as wide as length in the middle. T 3 about as long as T 2, T 3, and posterior tergites smooth and more delicate and membranous (Fig. 3 l). Hypopygium broad, hardly reaching apex of metasoma. Ovipositor sheath slightly protruding beyond apex of metasoma, almost glabrous (except for a few extremely short hairs apically) (Fig. 3 k). Colour. Body black, except T 1, lateral part of T 2 – T 7 light brown, dorsal part dark brown, and face slightly brown below sockets (Fig. 3 a). Palpi white. Tibia spurs pale yellow. Antenna brown to dark brown except scape and pedicel yellow-brown. Fore and middle legs off-white to yellow-brown, hind leg black except trochanter pale yellow, extreme basal femur and basal third of tibia yellow-brown. Wing membranes hyaline, slightly infumate, fore wing with pterostigma brown, veins pale brown to brown. Variation. Specimens from Brunei (Labi) with T 1 – T 2 white laterally, and specimens from Brunei (Kuala Belalong), Sarawak and Seram with yellow-brown head. Body length 2.7–3.1 mm. Male. Similar to female except T 1 longer with petiole at least 5.5 × longer than medial width and T 2 narrower. Body length 2.7–3.1 mm. Host. Unknown. Material examined. (NHMUK) Holotype • 1 ♀; Brunei, Seria swamp forest edge; M. C. Day; 14. ii – 4. iii. 1982; NHMUK 010639301. Paratype • 1 ♀; Brunei, Ulu Temburong N. P. (Malaise trap); M. C. Day; BMNH (E) 2011-106; 14. ii – 9. iii. 1982; NHMUK 010639751 • 2 ♀♀ 3 ♂♂; Brunei, Labi, mixed dipterocarp forest, 200 m; viii – ix. 1979; NHMUK 010826306, 010826288, 010826315, 010826623, 010826324 • 4 ♀♀ 6 ♂♂; Brunei, Kuala Belalong FSC 4 ° 34 ′ N, 115 ° 7 ′ E; 1800 m Malaise trap; iii. 1992; NHMUK 010826331, 010826319, 010826344, 010826346, 010826280, 010826347, 010826333, 010826329, 010826355, 010826349 • 6 ♀♀ 1 ♂; Malaysia, Sarawak (Borneo), 4 th Div. Gunung Mulu, RGS Exp.; 27. vi – 19. vii. 1978; H. Vallack; NHMUK 010826330, 010826319, 010826328, 010826320, 010826338, 010826345, 010826327, 010826334 • 3 ♂♂; Malaysia, Sarawak (Borneo), 4 th Div. Gn. Mulu, RGS Exp.; ii – iii. 1978; N. M. Collins; NHMUK 010826343, 010826321, 010826352 • 1 ♀; Malaysia, Sarawak (Borneo), 1 st Div. Lubok, Jita, 1 ° 12 ′ N, 110 ° 48 ′ E; 6–10. xi. 1976; P. S. Cranston; NHMUK 010826370 • 1 ♂; Indonesia, Seram, Solea village, Malaise trap, forest; VIII. 1987; coll. M. C. Day, BMNH (E) 1987-262; NHMUK 010826350. Distribution. Brunei, Malaysia (Sarawak), Indonesia (Seram). Etymology. The specific name carinatus, meaning “ keeled ” or “ carinate ”, refers to the presence of the medio-longitudinal carina on posterior mesoscutum. Remarks. This species is similar to W. nigratus, but differs in the following: vein cu-a of hind wing curved (sinuate in W. nigratus); scutellum without apical spine in lateral view (with an apical spine in W. nigratus); and mesoscutum strigose apically (smooth in W. nigratus).