Diplazon, Nees, 1819

Morishita, Shunsuke & Watanabe, Kyohei, 2021, -- Review- - of- - the- - genus Diplazon- - Nees, -- 1819 -- (Hymenoptera: -- Ichneumonidae Diplazontinae) -- from- - Japan, Zootaxa 4964 (1), pp. 103-122 : 105

Key to the Japanese species of Diplazon

1. Base of hind tibia white (Figs 5, 11, 22, 26)................................................................. 2

-. Base of hind tibia black (Figs 7, 17, 28, 32, 37, 41, 45)........................................................ 4

2. T II and T III polished and covered with large and dense punctures (Fig. 4). Propodeal carinae complete. Mesopleuron covered with large and dense punctures (Fig. 3)........................................... D. koreanus ­­ Balueva & Lee, 2015

-. T II and T III matt and strongly coriaceous (Figs 14, 25). Propodeum without carinae except for posterior part of lateral longitudinal carina and pleural carina. Mesopleuron covered with fine and dense punctures except for on and below speculum (Figs 13, 24).............................................................................................. 3

3. Posterior part of T III to apex of metasoma strongly compressed in females (Fig. 47), weakly compressed in males (Fig. 48). Mesopleuron completely black in females (Figs 11, 13). Transverse impressions distinct on T I and T II (Figs 47, 48)................................................................................... D. neoalpinus Zwakhals, 1979

-. Metasoma dorsoventrally depressed in both sexes (Figs 49, 50). Mesopleuron completely black or tinged with reddish-brown in females (Figs 22, 24). Transverse impressions distinct on T I to T III (Figs 49, 50)..... D. pectoratorius ( Thunberg, 1822)

4. Hind coxa black (Figs 41, 45). Mesopleuron polished and covered with punctures except for on and below speculum (Fig. 43). T II and T III rugulose but also covered with irregular punctures except for behind transverse impression of T III largely smooth (Fig. 44)...................................................................... D. varicoxa ( Thomson, 1890)

-. Hind coxa yellow or orange (Figs 7, 17, 28, 32, 37). Character states of mesopleuron, T II and T III various.............. 5

5. Hind tibia is banded as “black-white-black-orange” (Fig. 7). Metasoma black except for posterior part of T I to T III orange (Fig. 10). T I to T IV often entirely orange.......................................... D. laetatorius ( Fabricius, 1781)

-. Hind tibia is banded as “black-white-black” (Figs 17, 28, 32, 37). Metasoma without orange coloration (Figs 20, 31, 35, 40, 44)................................................................................................. 6

6. Mesopleuron largely smooth or covered with fine and sparse punctures (Figs 19, 30). Hind coxa yellow in both sexes (Figs 17, 28)................................................................................................. 7

-. Mesopleuron covered with dense punctures except for on and below speculum (Figs 34, 39, 43). Hind coxa orange in females (Figs 32, 37), orange or yellow in males.................................................................... 8

7. Mesopleuron covered with fine and sparse punctures (Fig. 19) in both sexes. T II 0.75–0.90 × as long as maximum width in both sexes. Face black except for a pair of longitudinal stripes along inner orbit yellow in females (Fig. 18), entirely yellow in males (Fig. 21)................................................................. D. pallicoxa Manukyan, 1987

-. Mesopleuron covered with fine and sparse punctures in females, largely smooth in males (Fig. 30). T II 0.55–0.70 (in females) or 0.74–0.86 (in males) × as long as maximum width. Face entirely yellow in both sexes (Fig. 29).. D. ryukyuensis Nakanishi, 1967

8. T II and T III covered with large and dense punctures (Fig. 35). Transverse impressions distinct on T I to T IV. Fore and mid coxae yellow (Fig. 32).......................................................... D. scutatorius Teunissen, 1943

-. T II and T III mainly rugulose but also covered with irregular punctures except for area behind transverse impressions of T III largely smooth (Fig. 40). Transverse impressions distinct on T I to T IV, but often indistinct on T IV. Fore and mid coxae orange except for basal part of fore coxa blackish-orange (Fig. 37)............................. D. tetragonus ( Thunberg, 1822)