Torymus acutissimus Matsuo 2020, n. sp.
Creators: name: Matsuo, Kazunori
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Torymidae
Torymus
Torymus acutissimus

description: Torymus acutissimus Matsuo n. sp.
Figs 1c, 5 e–f, 10a–d, 24c
Etymology. The specific name, acutissimus, is derived from the associated plant of this species.
Type material. Holotype: ♀ (BLKU), emerged on May 2010 from an unidentified gall midge that induces a gall on Quercus acutissima collected by K. Matsuo on 18 April 2010 from Azamidai, Kokonoe, Oita, Japan. Paratypes: 5 ♀ and 4 ♂, same data as the holotype (BLKU); 1 ♂, emerged on 5 May 2009 from an unidentified gall midge that induces a gall on Quercus acutissima collected by N. Wachi on 11 April 2009 from Azamidai, Kokonoe, Oita, Japan (BLKU); 1 ♂, emerged on 14 May 2008 from an unidentified gall midge that induces a gall on Quercus acutissima collected by Y. Abe on 11 May 2008 from Jizoubaru, Kokonoe, Oita (BLKU). Other specimens: 5 ♀, emerged on 5 May 2009 from an unidentified gall midge that induces a gall on Quercus acutissima collected by N. Wachi on 11 April 2009 from Azamidai, Kokonoe, Oita, Japan (BLKU).
Description. Female. Body length excluding ovipositor sheath 2.2–2.4 mm. Head green. Scape yellowish brown but darker apically; pedicel and flagellum brown. Mesosoma green. Fore wing hyaline. Fore and mid coxae yellow; hind coxa concolorous with mesosoma; all femora and tibiae yellow. Metasoma green (Fig. 1c).
Head 1.8–1.9× as wide as long in dorsal view; temple 0.2× as long as dorsal length of eye; POL 2.2–2.3× OOL; OOL 1.1–1.3× OD. Head 1.2× as wide as high in frontal view (Fig. 10a); eyes separated by 1.1× their height; malar space 0.4× height of eye; mouth 1.8× malar space; clypeus with apical margin produced, truncate medially.Antenna strongly clavate (Fig. 5e); scape 0.6–0.7× as long as height of eye, not reaching anterior ocellus; combined length of pedicel and flagellum 1.1–1.3× width of head; pedicel 1.3–1.5× as long as wide; anellus 1.1–1.3× as wide as long; F1 1.1–1.3× as long as wide, a little shorter than F2, with one or two sensilla; F2 1.1–1.3× as long as wide; F3 1.0–1.1× as long as wide; F4 0.8–1.0× as long as wide; F5 0.8–0.9× as long as wide; F6 0.6–0.7× as long as wide; F7 0.6× as long as wide; each funicular segment beyond F1 bearing longitudinal sensilla arranged in one row; C3 with a small tuft of micropilosity beneath.
Mesosoma 1.8–1.9× as long as wide; mesoscutum (Fig. 10b) with small piliferous punctures; mesoscutum reticulate; notaulus shallow; scutellum (Fig. 10c) 1.3–1.5× as long as wide, sculptured as posterior part of mesoscutum; frenal line absent; frenal area indicated by a difference in sculpture from the rest of scutellum, smoother and glabrous toward apex; dorsellum without median carina; propodeum (Fig. 10d) with superficial reticulation; lower mesepimeron 1.1–1.3× as long as wide. Fore wing (Fig. 24c) 2.5–2.6× as long as wide; costal cell 9.0–9.2× as long as wide, on upper surface with a setal row in distal 1/3, on lower surface with a setal row which is sparse medially and with scattered setae; basal cell closed, with a few setae; cubital setal line present; basal setal line present; speculum opened below; relative lengths of marginal vein: postmarginal vein: stigmal vein=8.4: 2.2: 1.0. Hind coxa 2.2–2.3× as long as wide, with dorsal carina basally; dorsal surface of hind coxa bare in basal half; hind femur 4.0–4.4× as long as wide; hind tibia with longer spur 1.1–1.2× as long as width of hind tibia, 0.3–0.4× length of basitarsus; hind tibia with shorter spur small, 0.3× length of longer spur.
Metasoma as long as mesosoma; posterior margin of metasomal tergum five entire; tip of hypopygium situated at 0.6 length of metasoma; ovipositor sheath as long as mesosoma, 1.8–1.9× as long as hind tibia.
Male. Differs from female as follows. Body length 2.2 mm. Temple 0.3× as long as dorsal length of eye; POL 2.8× OOL. Antenna stouter than that of female (Fig. 5f); scape bluish green; anellus transverse, 2.5 as wide as long; F1 0.8× as long as wide; F2–F7 0.8× as long as wide; longitudinal sensilla on each funicular segment arranged in one row. Fore wing 2.2× as long as wide; relative lengths of marginal vein: postmarginal vein: stigmal vein=6.0: 1.9: 1.0. Metasoma with coppery tint.
Distribution. Japan (Kyushu).
Host information. This species is a parasitoid of an unidentified gall midge (Diptera: Cecidomyiidae) that induces stem galls on Quercus acutissima Carruth (Fagaceae) (gall photo: fig. 26b, C–077 of Yukawa & Masuda 1996).
Remarks. Females of T. acutissimus are similar to T. pygmaeus Mayr, which is recorded from Austria (Graham & Gijswijt 1998), by having the following shared features: antenna strongly clavate; F1 a little shorter than F2; ovipositor sheath as long as mesosoma. However, females of T. acutissimus can be distinguished from T. pygmaeus by the following features: F1 with one or two sensilla (lacking sensilla in T. pygmaeus); frenal area indicated by a difference in sculpture from rest of scutellum (wholly reticulate in T. pygmaeus); dorsal surface of hind coxa bare in basal half (with a few setae in T. pygmaeus).
description: Published as part of Matsuo, Kazunori, 2020, A revision of Japanese Torymus Dalman (Hymenoptera: Torymidae), pp. 401-441 in Zootaxa 4758 (3) on pages 411-412, DOI: 10.11646/zootaxa.4758.3.1, http://zenodo.org/record/3734584