Tremex sudajii Togashi 2006
Creators: name: Shinohara, Akihiko
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Siricidae
Tremex
Tremex sudajii

description: Generic placement of Tremex sudajii Togashi, 2006
Tremex sudajii Togashi, 2006, belongs to the genus Eriotremex, as suggested by Naito (2019, 2020): Eriotremex sudajii (Togashi, 2006), comb. nov. I have examined the holotype deposited in NSMT and confirmed its generic placement. The holotype has the cell 2R 1 in the forewing about 0.5 times as long as the cell 3R1, the precornal basin densely punctate and pilose and convex medially, and the cercus present. These are generic characters of Eriotremex, which will place sudajii in this genus (Benson 1943; Smith 2010; Schiff et al. 2012). This species was described from a female specimen collected in Amami-ôshima Island, Kagoshima prefecture, and was later recorded from the main island of Kyushu (also in Kagoshima prefecture) by Narita (2018).
Key to Japanese species of Tremex
Female
1. Head entirely black; antenna black with apical half creamy white (Fig. 5A); forewing hyaline in basal half and dark infuscated in apical half (Fig. 7A); abdomen black, terga 2–8 each with creamy white spot laterally, those on terga 2, 3 and 8 usually larger, but not connected dorsally; cornus black (Fig. 10A). …............................................... T. apicalis
– Head not entirely black, at least with brownish spot on gena, usually mostly or entirely pale brown; antenna not as above, at least two or three basal antennomeres pale brown; forewing not as above, brownish hyaline, usually with some extent of dark or blackish brown infuscation; abdomen not as above, with pale brown bands or areas on some terga; cornus pale brown (Fig. 10B–L). ….......................................................................................... 2
2. Head black with dark brown spot on gena; antenna black with two or three basal and two or three apical antennomeres pale brown (Fig. 5B); forewing blackish infuscated, except for median part (parts of cells 1Rs, 1M and 2M) and posterior parts of cells 1Cu and 2Cu (Fig. 7B–D); abdomen, including precornal basin, black with tergum 2 mostly and tergum 8 in basal half pale brown, terga 3–7 each with pale brown spot laterally, those on terga 3 and 7 sometimes narrowly connected along anterior margin (Fig. 10B). …......................................................................... T. bicinctus
– Head pale brown to dark brown often with blackish areas, rarely mostly black; antenna various in coloration; forewing not as above; abdomen not as above, with more pale brown areas, precornal basin largely or entirely pale brown. …............ 3
3. Antenna blackish brown, with two to four basal and one apical antennomeres pale brown (Fig. 5C); pronotum (Figs 2A, 3C) long, its medial length (MPL) 0.74–0.95 (average 0.85) times as long as OOCL; hind tibia brown, often partly or mostly blackish, basal and apical halves not different in coloration (Fig. 6A); abdominal tergum 9 usually without black areas along posterior margin; precornal basin (Figs 2D, 10C, 11B) long, its length 0.74–0.98 (average 0.86) times as long as wide. … T. longicollis
– Antenna usually wholly pale brown (Fig. 5D–G, I), sometimes medially slightly darkened; pronotum long or short; hind tibia with basal half creamy white and apical half darker, usually dark brown to black (Fig. 6B–F); abdominal tergum 9 usually with black areas along posterior margin laterally; precornal basin (Fig. 10D–L) distinctly shorter than wide, its length at most 0.79 times as long as wide. …............................................................................... 4
4. Abdominal tergum 8 pale brown (Figs 1D, 10D, 11C) usually with irregular blackish mark in anterior part; precornal basin widest in anterior part (Figs 2E, 10D)............................................................ T. katayamai
– Abdominal tergum 8 pale brown with posterior 1/2–2/3 black (Fig. 10E, J–L) (often with pale brown marks in black area, Fig. 10F, G) or pale brown with black band medially (Fig. 10H, I); precornal basin widest in median or posterior part (Figs 2F, 10E–L). ............................................................................................. 5
5. Pronotum short, MPL 0.40–0.60 (average 0.52) times as long as OOCL (Figs 2B, 3E–G); forewing without distinct infuscation along anterior margin or outer margin (Fig. 7I, J).................................................. T. fuscicornis
– Pronotum comparatively long, MPL over 0.56 times as long as OOCL (Fig. 3H–L); forewing with distinct infuscation along anterior margin, particularly in cell 1R1 and cell 2R1, and along broad outer margin (Fig. 8).......................... 6
6. Pronotum (MPL) 0.56–0.68 (average 0.61) times as long as OOCL, usually with blackish longitudinal median line (Fig. 3H, I); hind tibia 1.22–1.42 (average 1.31) times as long as hind tarsomere 1; dorsal margin of hind tibia distinctly concave at middle (Fig. 6D); forewing with strong infuscation only around cell 1R1 and at base (Fig. 8A–D); abdominal tergum 8 pale brown, with broad transverse dark band at middle (Fig. 10H, I)................................................ T. nakanei
– Pronotum (MPL) over 0.75 times as long as OOCL, without blackish longitudinal median line (Fig. 3J–L); hind tibia less than 1.05 times as long as hind tarsomere 1; dorsal margin of hind tibia straight or very shallowly concave (Fig. 6E, F); forewing with distinct infuscation around cells R, 1R1 and usually 2R1 (Fig. 8E–J); abdominal tergum 8 pale brown with posterior 1/2–3/4 black (Fig. 10J–L).............................................................................. 7
7. Pronotum (MPL) 0.90–0.98 (average 0.93) times as long as OOCL (Fig. 3J); cell 3R 1 in forewing infuscated basally and along anterior margin (Fig. 8E, F); forewing 1.17–1.31 (average 1.23) times as long as ovipositor sheath; precornal basin without distinct black area in posterior part (Fig. 10J); apical sheath long, ovipositor sheath 2.51–2.70 (average 2.57) times as long as apical sheath................................................................................ T. contractus
– Pronotum (MPL) 0.75–0.85 (average 0.81) times as long as OOCL (Fig. 3K, L); cell 3R 1 in forewing not infuscated basally and along anterior margin (Fig. 8G–J); forewing 1.36–1.43 (average 1.38) times as long as ovipositor sheath; precornal basin with distinct black area in posterior part (Fig. 10K, L); apical sheath short, ovipositor sheath 2.69–2.75 (average 2.72) times as long as apical sheath............................................................................ T. okinawensis
Male (unknown for T. bicinctus and T. katayamai)
1. Abdominal terga entirely black (Fig. 12C, D)............................................................... 2
– Abdominal terga black with pale brown marks or almost entirely pale brown (Fig. 12A, B, E–H)...................... 3
2. Temple smooth with sparse punctures (Fig. 4B); antenna with 14 or 15 antennomeres (Fig. 5H); fore and mid tibiae and tarsi mostly blackish brown to black; forewing distinctly blackish infuscated in apical half with blackish veins (Fig. 9A); abdominal sterna 2–8 often with pale area medially. …........................................................ T. apicalis
– Temple densely punctate (Fig. 4D); antenna with 12 or 13 antennomeres (Fig. 5K); fore and mid tibiae and tarsi mostly brown to dark brown; forewing slightly brownish infuscated with brownish veins (Fig. 9C); abdominal sterna entirely black................................................................................................ T. fuscicornis
3. Temple, gena, antennal scape and pedicel and most of abdomen pale brown (Figs 4E, 5J, 12E); wings yellowish hyaline, without dark cloud (Fig. 9B)................................................................... T. longicollis
– Temple, gena and antennal scape and pedicel black (often dark brown in T. nakanei) (Fig. 4F–H); abdomen black with pale brown marks, at least anterior margin of each segment black (Fig. 12F–H); wings with dark cloud (Fig. 9D–F)............ 4
4. Antennal flagellum all black (Fig. 5L); pronotum short, MPL 0.59–0.71 (average 0.65) times as long as OOCL (Fig. 4F); hind tibia long, 1.48–1.56 (average 1.53) times as long as hind tarsomere 1 (Fig. 12A); wings dark infuscated except in basal 1/3 (Fig. 9D)..................................................................................... T. nakanei
– Antennal flagellum with narrow apex pale brown (Fig. 5N, M); pronotum long, MPL over 0.81 times as long as OOCL (Fig. 4G, H); hind tibia short, at most 1.25 times as long as hind tarsomere 1 (e.g. Fig. 12B); wings usually not as above........ 5
5. Pronotum (MPL) 0.88–1.00 (average 0.96) times as long as OOCL (Fig. 4G); abdominal tergum 8 entirely black (Fig. 12G); antenna with 14–16 (usually 15) antennomeres (Fig. 5M); body length 16–24 mm (n=18).................. T. contractus
– Pronotum (MPL) 0.81–0.84 (average 0.82) times as long as OOCL (Fig. 4H); abdominal tergum 8 largely pale brown (Fig. 12H); antenna with 13 or 14 antennomeres (Fig. 5N); body length 11–16 mm (n=4)...................... T. okinawensis
description: Published as part of Shinohara, Akihiko, 2023, The woodwasp genus Tremex (Hymenoptera, Siricidae) of Japan, pp. 1-40 in Zootaxa 5239 (1) on pages 9-10, DOI: 10.11646/zootaxa.5239.1.1, http://zenodo.org/record/7621749