3.3.4.Sirex ermak(Semenov, 1921) Figure 13 Paururus ermak Semenov, 1921, Russkoe Entomologicheskoe obozrenie, 17 [1917]: 92. (original description) Sirex ermak Semenov: Benson, 1943, Bulletin of Entomological Research 34: 30–32. (listed) Sirex ermak Semenov: Xiao et al., 1992, Economic Sawfly Fauna of China: 38–42. (described, figured, keyed) Sirex ermak Semenov: Xiao & Wu, 1983, Memoir of Forest Entomology: 2–5. (described, figured, keyed) Material examined. 4 ♀ Kadelate Village, Fuyun Country, Altai, Xinjiang, 2023-VIII-31, Ren L leg.; 6 ♀ 4 ♂ Kadelate Village, Fuyun Country, Altai, Xinjiang, 2024-VII-28 ~ 30, Ren L leg.; 4 ♀ Tiereketi Village, Habahe County, Xinjiang, 2017-VIII-5, 1035 m, Gao T and Lu ZB leg. Diagnosis. Females with forewings more or less darkened at least in the middle part (Fig. 13 A, B); vein 3 A of forewings basally present (Fig. 13 B); antennae completely blackish (Fig. 3 E); legs largely darkish; tarsal pad of metatarsomere 2 about 0.8 times as long as ventral length of tarsomere (Fig. 7 C). Males with flagellar basally yellowish (Fig. 3 F); abdomen segments I – III and VII – IX blackish, IV – VI light yellowish (Fig. 9 F). Metafemur largely blackish with a yellowish spot developed apically (Fig. 13 E). Female Description. Color: Head and thorax blackish with dark blue metallic reflections (Fig. 13 A, C). Antennae and palpi dark brownish to blackish (Fig. 3 E). Legs with coxae and femora black with dark blue metallic reflections, tibiae and tarsi dark brownish. Forewings with basal half almost clear and apical half pale brownish hue, sometimes with brownish moderately deepening before pterostigma, thus forms vague brownish bands (Fig. 13 B). Abdomen blackish with terga I and IX dark bluish metallic reflections while terga II – VIII dark purple metallic reflections in dorsal view (Fig. 9 E). — Head: Genae with pits 0.7–3.0 pit diameters apart (Fig. 6 E), vertex and postocellar area with pits less than 3.5 pit diameters apart (Fig. 5 E), and each pit diameter about 0.2–0.5 times as lateral ocelli. — Thorax: Mesoscutum with coarse net-like pits on median area, with indistinct transverse and longitudinal ridges in coarsely pitted area. Metatarsomere 2 in lateral view about 2.3–2.5 times as long as height, length about 1.15–1.25 times length of tarsomeres 3 + 4; tarsal pad about 0.8 times as long as ventral length of tarsomere (Fig. 7 C). Forewings vein 3 A basally present (Fig. 13 B). — Abdomen: Median basin of tergum IX with basal width 0.8–0.9 times as long as median length, maximum width 1.1–1.2 times as long as median length, median length 0.8–0.9 times of cornus length. Cornus in dorsal view short, with edges straight and angulate midway, its median length 1.0–1.2 times as long as maximum width of abdomen at junction of terga IX and X. Sheath. Basal section 1.04–1.10 times as long as apical section. Ovipositor. Pits near middle of annuli (the area at base of apical section of sheath) 0.06–0.1 times as long as annulus (Fig. 10 C), pits moderately decreasing in size toward ovipositor base, about 0.37 times as high as lancet height in lateral view, 0.5–0.6 times as long as pits height. Male Description. Color: Head, thorax and coxae black with dark blue metallic reflections (Fig. 13 D, E). Antennae with scape and pedicel blackish, flagella basally yellowish from flagellomere 1 to flagellomere 3–5, distal part of flagellar darkish (Fig. 3 F). Fore and mid legs with femora blackish (sometimes fore femora grades to brownish-yellow apically), tibiae and tarsi yellowish. Hind legs mostly blackish except a yellowish spot on the apical part of femora and metatarsomeres 4–5 yellowish. Forewings tinted light yellow and slightly pale brownish near outer margin. Abdomen with segments I – III and VII – IX black with dark blue metallic reflections, segments IV – VI light yellowish (Fig. 9 F). — Thorax: Metatibia about 4.1–4.2 times as long as maximum width (Fig. 8 C). Metatarsomere 1 in lateral view 3.3 times as long as maximum height. Distribution. Qinghai (Huzhu County, Banma County); Xinjiang (Fuyun County, Buerjin County). Host. Picea obovata; Larix sp. Note. A species distributed in both eastern and western China but not recorded in central China (Fig. 19). This species is similar to S. nitobei but can be distinguished from all Chinese Sirex based on the basally presence of vein 3 A.

Published as part of Ge, Sixun, Gao, Tai, Liu, Yizhou, Li, Jiale, Shi, Juan, Ren, Lili & Shi, Hongliang, 2025, A revision of the Wood wasp genus Sirex Linnaeus, 1760 [1761] (Hymenoptera: Siricoidea: Siricidae) in China, pp. 391-413 in Arthropod Systematics & Phylogeny 83 on pages 391-413, DOI: 10.3897/asp.83.e155906