Diplazon ryukyuensis Nakanishi, 1967

Morishita, Shunsuke & Watanabe, Kyohei, 2021, -- Review- - of- - the- - genus Diplazon- - Nees, -- 1819 -- (Hymenoptera: -- Ichneumonidae Diplazontinae) -- from- - Japan, Zootaxa 4964 (1), pp. 103-122 : 114-115

Diplazon ryukyuensis Nakanishi, 1967

(Figs 28–31)

Diplazon ryukyuensis Nakanishi, 1967: 34 .

Diagnosis. Face covered with fine and dense punctures. Antenna with 16–17 flagellomeres in both sexes. Mesopleuron covered with fine and sparse punctures except for on and below speculum in females, largely smooth in males (Fig. 30). Propodeum without carinae except for median longitudinal carina. Metasoma polished and dorsoventrally depressed. Transverse impressions distinct on T I to T IV (Fig. 31). T I 0.90–1.00 (in females) or 0.98–1.23 (in males) × as long as maximum width. T II 0.55–0.70 (in females) or 0.74–0.86 (in males) × as long as maximum width. T II and T III covered with large and dense punctures except for behind transverse impressions largely smooth (Fig. 31). Face entirely yellow in both sexes (Fig. 29). Scutellum largely yellow. Mesopleuron entirely black (Figs 28, 30). Coxae yellow (Fig. 28). Hind tibia is banded as “black-white-black” (Fig. 28). Metasoma black except for posterior transverse stripes of T I to T IV yellow (Fig. 31).

Specimens examined. JAPAN: 1♂, Kagoshima Pref., Tokunoshima Is., Amagi Town , Mt. Yamatogusuku 30. V 2007, K. Watanabe leg. ( KPMNH) ; 1♀, Okinawa Pref., 16. III. 1953, T. Shiraki leg. ( NIAES) ; 1♀, ditto, 22. III. 1953 ( NIAES) ; 1♀, ditto, 1. IV. 1953 ( NIAES) ; 1♀, Okinawa Pref., Okinawajima Is., Nago City , Buzena 4. XI. 1990, T. Taira leg. (LT) ( NIAES) ; 1♀, Okinawa Pref., Iriomotejima Is., Otomi 15–23. III. 1995, T. Matsumura leg. ( MT) ( NIAES) ; 2♀, Okinawa Pref., Iriomotejima Is., Otomi 29. XII. 2006, T. Ishizaki leg. ( KPMNH) ; 1♀, Okinawa Pref., Iriomotejima Is., Ohara , Fusatoruba 29. XII. 2006, J. Kantou leg. ( KPMNH) ; 1♂, Okinawa Pref., Ishigakijima Is., Mt. Omotodake , Takedarindo 24. III. 2010, H. Sawada leg. ( KPMNH) ; 1♂ (paratype), Okinawa Pref., Iriomote- jima Is. 15–16. XI. 1963, G. A. Samuelson leg. ( MT) ( MNHAH) .

Distribution. Japan (Tokunoshima Is., Okinawajima Is., Ishigakijima Is., and Iriomotejima Is).

Bionomics. Unknown.

Remarks. This is the first record of this species from Tokunoshima Island. This species resembles D. orientalis with both species having yellow coxae and the metasoma with large and dense punctures, but it can be distinguished by the following combination of character states: face entirely yellow in females (black expect for a pair of longitudinal yellow stripes along inner orbit in female of D. orientalis ); mesopleuron covered with fine and sparse punctures in females, largely smooth in males (covered with large and dense punctures in both sexes of D. orientalis ); the minimum distance between punctures of mesopleuron 0.25–0.50 × as long as the diameter of punctures (0.71–0.83 in D. orientalis ), T II 0.74–0.86 × as long as maximum width in males (0.60 in males of D. orientalis ) (Table 1).