Tremex okinawensis Togashi 1997
Creators: name: Shinohara, Akihiko
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Siricidae
Tremex
Tremex okinawensis

description: Tremex okinawensis Togashi, 1997
(Figs 3K, L, 4H, 5G, N, 6F, 8 G-J, 9F, 10K, L, 11F, 12H, 15; Tables 1–4)
Tremex okinawensis Togashi, 1997: 2; Yafuso, 2002: 328; Togashi, 2006: 939; Taeger et al., 2010: 108; Kawano, 2014: 19; Naito, 2019: 20; Naito, 2020: 467.
Tremex kurokivorus Togashi, 2006: 941; Taeger et al., 2010: 108; Naito, 2019: 20; Naito, 2020: 467. New synonym.
Diagnostic characters. Female. Length without ovipositor 19–25 mm. Head pale brown, with clypeus and malar space black. Antenna wholly pale brown (Fig. 5G). Thorax black, with pronotum, propleuron, parascutal lobe, part of or entire mesoscutellum, part of metanotum pale brown; pronotum (Fig. 3K, L) without blackish longitudinal median line; mesoscutum and mesopleuron sometimes marked with pale brown (Fig. 3K). Fore and mid legs pale brown, with part of coxa and sometimes parts of trochanter and femur blackish to black; hind leg black, with tibia and tarsus dark brown (basal halves of tibia and tarsomere 1 creamy white). Forewing with distinct infuscation around cells R, 1R1, 2Rs, 3M, 3Cu and usually 2R1; cell 3R1 not infuscated basally and along anterior margin (Fig. 8 G–J). Abdomen black, with following pale brown: Usually anterior margin of tergum 1, most of tergum 2 (except for posterior margin), lateral spot on terga 3–6, narrow anterior margin of tergum 7, anterior 1/3–1/2 of tergum 8 (except for anterior lateral corner), large mark on tergum 9, covering anterior half of precornal basin and large lateral surface, and cornus. Pale brown on head, thorax and tergum 9 often with dark orange tint. Antenna with 14–16 antennomeres. Pronotum (Fig. 3K, L) with MPL 0.75–0.85 (average 0.81) times as long as OOCL. Hind tibia 0.99–1.05 (average 1.01) times as long as hind tarsomere 1; dorsal margin of hind tibia straight or very shallowly concave (Fig. 6F). Forewing 1.36–1.43 (average 1.38) times as long as ovipositor sheath. Abdominal tergum 8 1.00–1.27 (average 1.10) times as long as terga 5–7 combined; precornal basin short, 0.57–0.77 (average 0.63) times as long as wide, widest in posterior part (Fig. 11F); ovipositor sheath 2.69–2.75 (average 2.72) times as long as apical sheath.
Male. Length 11–16 mm. Head, antenna, thorax and legs black except as follows: terminal antennomere partly or entirely pale brown (Fig. 5N). Fore and mid femora (except for basal parts), tibiae and tarsi pale reddish brown and extreme base of hind tibia pale brown. Wings dark brown, basal and midapical parts more hyaline (Fig. 9F). Abdomen (Fig. 12H) pale brown, with following black: terga 1 and 2, basal part (extending posteriorly along median line) of terga 3–8, entire sternum 2, anterior and posterior margins and median line of sterna 3–7, most of sternum 8 (except for large lateral brownish spots) and sternum 9 (except for large median and posterior part). Antenna with 13 or 14 antennomeres. Pronotum (Fig. 4H) with MPL 0.81–0.84 (average 0.82) times as long as OOCL. Hind tibia short, 1.18–1.25 (average 1.22) times as long as hind tarsomere 1.
Type material examined. ♀ (holotype of T.okinawensis),“ Benoki, Okinawa Is., 3.V.1971, K.Miyagi ”“Holotype Tremex okinawensis Togashi ” (NSMT). ♀ (holotype of T. kurokivorus), “ Ôyama, Okinoerabu-jima, Nakaharakuroki [= Symplocos nakaharae], 2003.10.12 coll. wood, 2004.8.30 em., H. Makihara ” “Holotype Tremex kurokivorus sp. nov. ” (NSMT).
Other material examined. 3♀4³ (3 ³ from Amami-ôshima Island and 3♀ 1³ from Okinawa Island). See Appendix for collection data.
Distribution (Fig. 15). Japan: Nansei Islands (Amami-ôshima (new record), Okinoerabu and Okinawa Islands).
Host plant. Symplocaceae: Symplocos nakaharae (Hayata) Masam. (Togashi 2006, and the Japanese name on the label).
Remarks. This species has been found only in northern part of the Nansei Islands and the male is described here for the first time. All the specimens were collected in late April to early May. The female is characterized by the pale brown antenna (Fig. 5G), the long pronotum (Fig. 3K, L), the hind tibia about as long as the hind tarsomere 1 and with the basal half creamy white and the apical half dark brown (Fig. 6F), the forewing with distinct infuscation around the cells R, 1R1, 2Rs, 3M, 3Cu and usually 2R1, the cell 3R1 not infuscated basally and along anterior margin (Fig. 8G–J), the abdominal tergum 8 pale brown with posterior 1/2–3/4 black, the abdominal tergum 9 usually with black areas along the posterior margin laterally and the short precornal basin (Fig. 10K, L). The male is characterized by the entirely black head (Fig. 4H), the antenna black with the narrow apex pale brown, with 13 or 14 antennomeres (Fig. 5N), the long pronotum (Fig. 4H), the short hind tibia (Fig. 12H), the dark brown wings with the basal and midapical parts more hyaline (Fig. 9F) and the black abdomen with pale brown marks (tergum 8 largely pale brown) (Fig. 12H).
Togashi (2006) distinguished T. kurokivorus from T. okinawensis by the differences in the color patterns of the mesoscutum, the fore and mid coxae, and the terga 8 and 9 of the abdomen, the shape of the antennal pedicel, the relative lengths of the flagellomeres 1 and 2, and the form of the precornal basin. These differences were actually between the female holotypes of T. kurokivorus and T. okinawensis, because Togashi examined only the holotypes of the two species. I have examined five female specimens, including the holotypes of both species. Of these, the holotype of T. okinawensis (Figs 3K, 8G, 10K) is the palest specimen having the mesoscutum, mesoscutellum, mesopleuron and the fore and mid coxae largely pale brown, whereas these areas are mostly or entirely black in other specimens, including the holotype of T. kurokivorus (Figs 3L, 8I, 10L). Otherwise, the five specimens show no significant differences and here I propose to treat T. kurokivorus Togashi, 2006, as a synonym of T. okinawensis Togashi, 1997.
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 28-32, DOI: 10.11646/zootaxa.5239.1.1, http://zenodo.org/record/7621749