Tremex nakanei Takeuchi 1955
Creators: name: Shinohara, Akihiko
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Siricidae
Tremex
Tremex nakanei

description: Tremex nakanei Takeuchi, 1955a
(Figs 2C, 3H, I, 4F, 5E, L, 6D, 8A–D, 9D, 10H, I, 12A, F, 15; Tables 1–4)
Tremex fuscicornis: Miyatake, 1950: 38; Nakamura & Fujishita, 1974: 104; Nagase, 2008a: 3. Not Fabricius, 1787, in part.
Tremex nakanei Takeuchi, 1955a: 3, 7; Takeuchi, 1962: 4, 10; Kojima et al., 1962: 8; Kurosawa, 1965: 18; Okutani, 1965: 463; Okutani, 1967: 44; Okutani, 1970: 27; Okutani, 1971: 18; Smith, 1978: 100; Terayama, 1982a: 24; Terayama, 1982b: 25; Shimoyama, 1986: 7; Abe & Togashi, 1989: 558; Sakamoto, 1997: 24; Togashi, 1997: 2; Nagase, 2004: 1254; Naito et al., 2004: 68; Takahashi, 2004: 16; Togashi, 2006: 939; Yoshida, 2006: 105; Nagase, 2008b: 41; Matsumoto et al., 2009: 27; Funamoto, 2010: 10; Taeger et al., 2010: 108; Takahashi, 2013: 31; Saito, 2013: 60; Saito & Higurashi, 2017: 53; Shirota, 2017: 52; Saito, 2018: 61; Nagase & Watanabe, 2018: 950; Naito, 2019: 20; Naito, 2020: 467; Konishi, 2020: 51; Ogawa & Shinohara, 2022.
Tremex kaedei Togashi, 1997: 3; Togashi, 1998: 45; Togashi, 2006: 939; Taeger et al., 2010: 108; Naito, 2019: 20; Naito, 2020: 467. New synonym.
Kimadara-hiraashikibachi [Tremex fuscicornis], Takakuwa, 2004: 31.
Hiraashikibachi-no 1 Shu [Tremex sp.], Anonymous, 2013.
Diagnostic characters. Female. Length without ovipositor 20–30 mm. Head pale brown, usually with blackish mark around ocellar area. Antenna wholly pale brown (Fig. 5E). Thorax black, with dorsal surface of pronotum (usually with blackish longitudinal median line), parascutal lobe and sometimes mesoscutum, mesoscutellum and mesopleuron partly pale brown. Legs with coxae and femora blackish brown to black; trochanters usually brown and tibiae and tarsi pale brown; mid and hind tibiae with basal halves creamy white and apical halves dark brown to black; mid and hind tarsomeres1 basally creamy white. Forewing with strong infuscation only around cell 1R1 and at base (Fig. 8A–D); cell 2R1 and anterior part of cell 3R1 dark yellowish, rest of cell 3R1 and cells 2Rs, 3M and 3Cu weakly infuscated. Abdomen black, with following pale brown: Sometimes lateral round spot on tergum 1, most of tergum 2, anterior margins of terga 3 and 7, very narrow anterolateral parts or very narrow anterior margins of terga 4–6, anterior 1/3–1/4 (except for anterior lateral corner) and posterior 1/3–1/2 of tergum 8, posterior half (except for narrow lateral posterior margin) and dorsal part of ventral divided part of tergum 9, including entire precornal basin, and cornus. Antenna with 13–15 antennomeres. Pronotum (Fig. 3H, I) short, MPL 0.56–0.68 (average 0.61) times as long as OOCL. 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 1.24–1.37 (average 1.29) times as long as ovipositor sheath. Abdominal tergum 8 0.79–1.06 (average 0.96) times as long as terga 5–7 combined; precornal basin short, 0.56–0.73 (average 0.63) times as long as wide, widest in posterior part (Fig. 10H); ovipositor sheath 2.62–2.86 (average 2.72) times as long as apical sheath.
Male. Length 11–20 mm. Black except as follows: temple, antennal scape and pedicel and parascutal lobe often marked with dark brown. Fore and mid legs with apex of femur, tibia and tarsus often pale or dark brown. Wings dark infuscated except in basal 1/3 (Fig. 9D). Abdominal segments 3-8 and sternum 9 with brown marks (often faded and inconspicuous); brown mark on each of terga 3–8 usually divided into paired lateral marks, or otherwise forming broad band occupying posterior 1/2–2/3 of each tergum (usually so on terga 7 and 8); brown mark on each of sterna 3–8 usually divided into paired spots. Antenna with 12–14 antennomeres. Pronotum (Fig. 4F) short, MPL 0.59–0.71 (average 0.65) times as long as OOCL. Hind tibia long, 1.48–1.56 (average 1.53) times as long as hind tarsomere 1.
Type material examined. ♀ (holotype of T. nakanei), “25, VII, 1946, Simajima, Shinano [=Nagano Pref.], Takeuchi/T. Nakane ” “ Tremex nakanei sp. nov. ” “ HOLOTYPE Tremex nakanei Takeuchi, 1955, det. A. Shinohara, 1979” (NSMT), in poor condition, covered with dead mold. ♀ (holotype of T. kaedei), “ Hirosaki, Aomori Pref., 11. IV. 1976, S. Satoh ” “Host: Acer sp. ” “ Holotype Tremex kaedei Togashi ” (NSMT), in perfect condition. 1³ (paratype of T. kaedei), Hirosaki, Aomori Pref., 11. IV. 1976, S. Satoh (NSMT).
Other material examined. 22♀ 5³ (1♀ 1³ from Hokkaido, 15♀ 3³ from Honshu, 5♀ 1³ from Shikoku and 1♀ from Kyushu). See Appendix for collection data.
Distribution (Fig. 15). Japan (Hokkaido, Honshu, Shikoku, Kyushu).
Host plants. Sapindaceae: Acer micranthum Siebold et Zucc. (Kojima et al. 1962), Aesculus turbinata Blume (Takahashi 2013). Betulaceae: Carpinus tschonoskii Maxim. (Okutani 1970). Rutaceae: Phellodendron amurense Rupr. var. amurense (Anonymous 2013). Cannabaceae: Celtis sinensis Pers. (Funamoto 2010), Celtis jessoensis Koidz. (Takahashi 2013). Juglandaceae: Pterocarya rhoifolia Siebold et Zucc. (new record).
Remarks. This is a Japanese endemic species with adult emergence in early to mid-summer (Table 4). The female of T. nakanei is characterized by the short pronotum (Fig. 3H, I), the long hind tibia, whose dorsal margin is distinctly concave medially (Fig. 6D), short tarsomere 1, the forewing usually with distinct cloud around the cell 1R1 (Fig. 8A–D), the pale brown abdominal tergum 8 with a black broad transverse band at middle (Fig. 10H, I) and the comparatively short apical sheath of the ovipositor. The male is characterized by the entirely black antennal flagellum (Fig. 5L), short pronotum (Fig. 4F), the long hind tibia and short tarsomere 1 (Fig. 12A), the wings dark infuscated except in basal 1/3 (Fig. 9D) and the black abdomen with often obscure pale brown marks on the segments 3–8 and the sternum 9 (Fig. 12A, F).
Tremex kaedei was described from Hirosaki, northern Honshu, Japan and was included in the keys by Togashi (1997, 2006) and Naito (2020). In those keys, T. kaedei was separated from T. fuscicornis and T. nakanei by the length of the abdominal tergum 8 and the color of the mesoscutum and the abdominal tergum 1 (Togashi 1997), by the length of the abdominal tergum 8 and the color of the abdominal tergum 1 (Togashi 2006) and the color of the abdominal tergum 1 (Naito 2020). As discussed above, these characters show large variations and cannot be used for species distinction. After a direct comparison of the holotypes of T. nakanei and T. kaedei, here I propose to treat them as synonyms.
This species has been recorded from Hokkaido (Togashi 1998, as T. kaedei), Aomori (Shimoyama 1986; Togashi 1997, as T. kaedei), Saitama (Terayama 1982a), Tokyo (Kurosawa 1965; Takahashi 2004), Chiba (Saito 2013, etc.), Kanagawa (Terayama 1982b, etc.), Nagano (Takeuchi 1955a), Niigata (Takahashi 2013), Toyama (Anonymous 2013), Kyoto (Konishi 2020),? Hyogo (Naito et al. 2004; see comments below) and Shimane (Sakamoto 1997) prefectures in Honshu, Ehime (Miyatake 1950, as T. fuscicornis) and Kochi (Kojima et al. 1962) prefectures in Shikoku and Miyazaki prefecture in Kyushu (Ogawa & Shinohara 2022). Here I record this species from Yamanashi, Gifu, Mie and Tottori prefectures for the first time (see Appendix for collection data).
Naito et al. (2004) recorded this species from Hyogo prefecture based on a female with the collection data “Oginosen, 1977, VII. 17, Toyama Masao (KU)”. I have examined a female specimen labeled “Mt. Oginosen, Tottori, 17.VII.1977, M. Toyama,” which was formerly kept in Kobe University and probably the same specimen as that referred to by Naito et al. (2004). The occurrence of T. nakanei in Hyogo prefecture needs confirmation.
According to the label data, one specimen from Keta, Shizuoka prefecture (see Appendix) has emerged from the wood of Pterocarya rhoifolia (Juglandaceae), which is newly recorded here as the host plant of T. nakanei.
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 26-27, DOI: 10.11646/zootaxa.5239.1.1, http://zenodo.org/record/7621749