Tremex apicalis Matsumura 1912
Creators: name: Shinohara, Akihiko
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Siricidae
Tremex
Tremex apicalis

description: Tremex apicalis Matsumura, 1912
(Figs 1A–C, 3A, 4A, B, 5A, H, 7A, 9A, 10A, 12C, 13; Tables 1–4)
Tremex apicalis Matsumura, 1912: 23; Yano, 1917: 121; Matsumura, 1930: 62; Matsumura, 1931: 79; Matsumura, 1932a; 35, 50; Yano, 1932: 474; Gussakovskij, 1935: 67; Takeuchi 1938: 193; Kono & Sugihara, 1939: 109; Benson, 1943: 41; Maa, 1949: 140; Takeuchi, 1949: 47; Miyatake, 1950: 39; Takeuchi, 1950: 1333; Takeuchi, 1955a: 2, 6; Takeuchi, 1955b: 115; Kojima et al., 1962: 8; Takeuchi, 1962: 3, 9; Okutani, 1965: 463; Okutani, 1967: 44; Okutani, 1971: 18; Tanaka, 1971: 201;? Kondo & Miyake, 1976: 3 (see comments below); Smith, 1978: 93; Tanaka, 1979: 459; Shimoyama, 1986: 7; Abe & Togashi, 1989: 558; Murota & Kurokawa, 1985: 246; Xiao et al., 1992: 54; Haneda et al., 1998: 324; Lee et al., 1998: 298 (in part); Shinohara, 2000: 296; Shinohara, 2001: 286; Nakamura, 2003: 266; Nagase, 2004: 1254; Naito et al., 2004: 68; Shinohara, 2005: 230; Yoshida, 2006: 105; Nagase, 2008b: 47; Taeger et al., 2010: 107; Shinohara, 2014: 472; Kuramitsu et al., 2016: 71; Sundukov, 2017: 113; Nagase & Watanabe, 2018: 950; Naito, 2019: 19; Kuramitsu et al., 2019: 37; Lee et al., 2019: 14; Naito, 2020: 467; Shinohara & Hara, 2020: 184; Hara et al., 2021: 166.
See Smith (1978) and Lee et al. (2019) for more synonyms and references.
Diagnostic characters. Female (Fig. 1B). Length without ovipositor 18–35 mm. Black, with following creamy white: Apical half of antenna (Fig. 5A), tibia (except apical part), tarsomere 1 (except apical part) and 5, anterior half of each of terga 2 and 3 (medially interrupted) and lateral spots on terga 4–8. Forewing hyaline in basal half and dark infuscated in apical half (Fig. 7A). Antenna with 14–16 antennomeres. Pronotum (Fig. 3A) short, MPL 0.46– 0.62 (average 0.54) times as long as OOCL. Hind tibia 1.14–1.29 (average 1.18) times as long as hind tarsomere 1; dorsal margin of hind tibia straight or very shallowly concave. Forewing 1.10–1.28 (average 1.21) times as long as ovipositor sheath. Abdominal tergum 8 0.73–1.16 (average 0.97) times as long as terga 5–7 combined; precornal basin 0.63–0.72 (average 0.68) times as long as wide; ovipositor sheath 2.21–2.43 (average 2.31) times as long as apical sheath.
Male (Fig. 1C). Length 17–30 mm. Black, with slight bluish reflections. Wings hyaline, apical half distinctly blackish infuscated, veins blackish (Fig. 9A). Abdominal sterna 2–8 often with whitish area medially. Temple smooth with sparse punctures. Antenna with 14 or 15 antennomeres. Pronotum (Fig. 4A) short, MPL 0.56–0.62 (average 0.59) times as long as OOCL; Hind tibia short, 1.22–1.37 (average 1.29) times as long as hind tarsomere 1.
Material examined. 77♀ 130³ (1♀ 5³ from Korea, 9♀ 11³ from Hokkaido, 60♀ 101³ from Honshu, 6♀ 12³ from Shikoku and 1♀ 1³ with no locality data). See Appendix for collection data.
Distribution (Fig. 13). Japan (Hokkaido, Honshu, Shikoku,?Kyushu (see discussion below)). Korea. China (Jilin to Liaoning, Zhejiang, Shaanxi and Sichuan (see Xiao et al. 1992, for more details)). Russia (Sakhalin, Zabaikalskii Terr. (Sundukov 2017)).
Host plants. Betulaceae: Alnus japonica (Thunb.) Steud. (Hara et al. 2021), Betula platyphylla Sukaczev var. japonica (Miq.) H.Hara (Shinohara & Hara 2020). Cornaceae: Swida macrophylla (Wall.) Soják (Kuramitsu et al. 2019). Eupteleaceae: Euptelea polyandra Siebold et Zucc. (Kuramitsu et al. 2019). Fagaceae: Quercus myrsinifolia Blume (Okutani 1967), Lithocarpus edulis (Makino) Nakai (Shinohara & Hara 2020). Juglandaceae: Juglans mandshurica Maxim. var. sachalinensis (Komatsu) Kitam. (Hara et al. 2021). Magnoliaceae: Magnolia liliiflora Desr. (Kuramitsu et al. 2019). Oleaceae: Fraxinus platypoda Oliv. (Kuramitsu et al. 2019). Rosaceae: Cerasus x yedoensis (Matsum.) Masam. et S.Suzuki (Okutani 1967). Salicaceae: Populus sp. (Maa 1949). Sapindaceae: Acer palmatum Thunb. (Kono & Sugihara 1939), Acer pictum Thunb. (Kojima et al. 1962).
Remarks. This species is well characterized by the black and creamy white coloration as described above and it is easily distinguished from the other Japanese Tremex species by the characters given in the key.
It is apparently the most common species of Tremex in eastern Japan. In the lowlands of Kanto region in central Honshu, the adults occur in May sometimes in numbers on the trunk of dead or weakened host trees (Fig. 1A). In western Honshu, this species is rare; I have examined a series from Kyoto prefecture collected in 1937 to 1953 (see Appendix) and there are only two reliable published collection records from Hyogo prefecture (fig. 142 in Naito et al. 2004). In Okayama prefecture, Kondo & Miyake (1976) gave collection records of three males of T. apicalis collected in late July, early August and mid-September, respectively. These males may not belong to T. apicalis, because this species occurs only in spring (Table 4) and the collection data of the specimens are late even though the recorded localities are on the mountains. It is interesting that another species, T. contractus, occurs only in western parts in Honshu (eastern limits are Kyoto and Nara prefectures), almost replacing T. apicalis. Tremex apicalis and T. contractus, whose adults occur only in spring (Table 4), have nearly allopatric distribution in Honshu. Tremex apicalis is distributed in northern and eastern central parts, from Aomori prefecture to Kyoto prefecture (with a few records, partly doubtful, from Hyogo and Okayama prefectures, as noted above), and T. contractus has been found only in western parts, from Kyoto and Nara prefectures to Hiroshima prefecture (Anonymous 2004; present work) (Fig. 13).
The specimens from Fukushima, Nagano, Tokushima and Kochi prefectures listed in Appendix represent the first collection records from these prefectures.
As far as I know, Takeuchi (1955a, b) was the first to include Kyushu in the distribution of this species, but he did not give any collection record. I was not able to find any specimens or any published collection records of T. apicalis from Kyushu. The occurrence of T. apicalis in Kyushu needs confirmation. A Korean male specimen recorded by Lee et al. (1998) as T. apicalis from “Suigen” actually belongs to T. fuscicornis (see discussion under T. fuscicornis).
Matsumura (1912) mentioned “the larvae bore in the stem of Abies sachalinensis ” and Matsumura (1932a) mentioned “this is common in a newly cut pine forest, perhaps boring in the stem of Abies and Picea spp. ” These host records are most probably erroneous.
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 10-14, DOI: 10.11646/zootaxa.5239.1.1, http://zenodo.org/record/7621749