The Japanese species of Monoctenus (Hymenoptera: Diprionidae) Author Hara, Hideho Nishi 4 - Kita 3 - 4 - 29, Bibai, Hokkaido, 072 - 0033 Japan. Author Nagase, Hirohiko 81 Nikaidô, Kamakura, Kanagawa, 248 - 0002 Japan. text Zootaxa 2023 2023-12-05 5380 6 541 561 https://www.mapress.com/zt/article/download/zootaxa.5380.6.3/52407 journal article 281814 10.11646/zootaxa.5380.6.3 a25f1d30-c455-4ccc-9b79-0d401a2896c2 1175-5326 10259644 AA915DFA-58B9-428D-AF5D-193E3295AB04 Monoctenus fujisanus Togashi, 2001 ( Figs 5A 2b , 6A 2b, B2b , 7A 2, B2 , 14) Monoctenus fujisanus Togashi, 2001: 44 ; Taeger et al. 2010: 211 ; Yoshida 2010: 28 ; Hara 2019: 46 ; Hara 2020: 287 . Monoctenus itoi : Togashi 2001: 41 (part, female); Hara 2020: 287 (part, female). Not Okutani, 1958 . Additional description . Female . Length 7.5–8.7 mm . Figs 5A 2b , 14A, B. Head capsule black, with supraclypeal area yellow to red brown, anterior tentorial pit and its surroundings usually red yellow to red brown; clypeus dorsomedially dark brown, dorsally widely red yellow or almost entirely red yellow; vertex posteromedially dark brown or posteriorly widely red yellow; frons sometimes anterolaterally red yellow ( Fig. 14C–J ). Labrum brown to black. Prepectus red yellow or black. Postspiracular sclerite black. Mesoscutum black on posterolateral sunken part and often on lateral part of lateral lobe ( Fig. 14L–N ). Mesoscutellum sometimes narrowly red yellow anteriorly. Mesepisternum black ( Fig. 14B ), sometimes with pectus red yellow ( Fig. 5A 2b ). Abdomen without pale parts ( Fig. 14A, B ). Clypeus without median furrow ( Fig. 14G–J ); ventral edge widely concave. Antenna with 15–17 antennomeres ( Figs 7A 2 , 14K); flagellomere 6 in lateral view with breadth including serration 1.1–1.5 × dorsal length. Valvula 3 ( Fig. 14O–Q ) in dorsal view tapering and with apex narrowly rounded or pointed, in lateral view with apex narrowly rounded and dorsal edge nearly straight. Lance in lateral view with dorsal edge gently rounded near middle and almost straight from middle to near apex ( Fig. 14R ); radix long. Lancet with 9–10 annuli ( Figs 7B 2 , 14S , T); length from ventral end of ctenidium 1 to apex 4.4–5.3 × breadth; ctenidia 1 and 2 parallel, inclined posteriorly ( Fig. 7B 2 ); ctenidia 3 and 4 converging dorsally; ctenidia 4–7 parallel, inclined anteriorly. FIGURE 14 . Monoctenus fujisanus , female. A, B, Holotype, dorsal and ventrolateral; C–F, head, dorsal; G–J, head anterior; K, antenna, inner; L–N, thorax dorsal; O–Q, valvula3, dorsal, lateral and posterior; R, lance; S, T, lancet. Male . Unknown. Material examined . Holotype ( Figs 14A–C, G, K, M, O–Q, S ): ♀ , labelled “ Tenshokyo , 1000m , Mt. Fuji , Shizuoka Pref. , 20. VI. 1989 , H. Ishikawa”, “DIP-01” and “Holotype Monoctenus fujisanus n. sp. ” . Other material examined: 1♀ , Tochigi Pref. , Otawara, Shimoishigami, 18. V. 2010 , E. Katayama ( Figs 5A 2b , 6A 2b ) (deposited in the collector’s collection) ; 1♀ , Tochigi Pref. , Yaita , Happogahara , 21. VI. 1987 , T. Saito (cited as M. itoi by Hara 2020 ) ; 1♀ , Kanagawa Pref. , Hakone , Mt. Komagatake , 5. VI. 2004 , H. Nagase (deposited in Kanagawa Prefectural Museum of Natural History , Odawara ) ; 1♀ , Yamanashi Pref. , Nambu , Toshima , 5. V. 1977 , A. Shinohara ( Figs 7A 2 , 14F, J, N, T) (treated as M. itoi by Togashi 2001 ) ; 1♀ , Nara Pref. , Yoshino , 2. VI. 1916 , Takeuchi ( Fig. 14E, I ) ; 1♀ , Hyogo Pref. , Sasayama , 200m , 15. V. 1983 , T. Naito ( Figs 6B 2b , 7B 2 , 14D, H, L, R) . Distribution . Japan (Honshu) ( Togashi 2001 ). Host plant . Unknown. Remarks . This species is separated from other Monoctenus species as stated in the key and the remarks of M. cryptomeriae . Togashi (2001) described M. fujisanus as a closely allied species to M. decoratus and separated their females by the differences in the angle of the front edge of a scutellum, the length ratio of an antennomere 3 to an antennomere 2, the number and shape of the annuli of a lancet, the length of a female cercus and the shape of a clypeus. However, these character states except for the shape of a lancet are variable in our material and not useful to distinguish them. This species has considerable variation in the coloration of the female head and mesoscutum ( Fig. 14C–J, L–N ). Togashi (2001) and Hara (2020) regarded the richly light-marked females as M. itoi . However, the females with different colorations do not have significant morphological differences, and their color differences are continuous.