Miridiba (Miridiba) kuraruana Nomura, 1977

Li, Chun-Lin, Yang, Ping-Shih & Wang, Chuan-Chan, 2015, A review of the genus Miridiba Reitter (Coleoptera: Scarabaeidae: Melolonthinae) of Taiwan, Zootaxa 3955 (4), pp. 521-536 : 523-524

Miridiba (Miridiba) kuraruana Nomura, 1977

Figs. 1 , 7 , 13, 19, 25, 26

Miridiba kuraruana Nomura, 1977: 89 (type locality: Kenting, Pingtung County, Taiwan; holotype in the National Museum of Nature and Science, Tsukuba, Japan, examined); Smetana & Král 2006: 222 (catalog); Coca-Abia 2008: 680 (remarks, key).

Specimens examined. TAIWAN. Pingtung County: Kentung, 23/VI/2001, W.-S. Lin. (1 male, 2 females, NMNS); Kenting Nat. Pk., 28-29/VI/1991, C. K. Starr (1 male, NMNS); Nan Jen Shan, 2/IV/1991, T.-S. Tseng (1 male, CCLI); Liangshan, 20/IV/1991, K.-T. Wu (1 female, CCLI).

Redescription. Male ( Fig. 1 ). Body length 18.0– 20.6 mm; width across humeri 8.4–9.4 mm. Color dark reddish brown to rufotestaceous on head and pronotum; reddish brown on elytra, venter, and legs; moderately shiny. Antennae yellowish brown to reddish brown. Dorsum of head covered with robust, brown setae; setae on pronotum and elytra mostly tiny (observable only using high magnification); most setae shorter than diameter of puncture with exception of a few long, recognizable, robust setae on base of elytra, sutural costa, and in front of scutellum (Fig. 13, indicated by arrow). Head: Surface densely punctate; punctures large, each bearing a short, erect seta. Clypeus ( Fig. 7 ) with apex moderately bilobed and reflexed; lobes round, widened at base.

Clypeofrontal suture clearly defined. Basal carina curved at middle, distinctly raised. Antenna with 9 antennomeres, club subequal to length of antennomeres 2–6 combined. Thorax: Pronotum widest at middle, anterolateral angles not protuberant ( Fig. 7 ), basolateral angles obtuse, lateral margin coarsely serrate, moderately reflexed; lateral declivities with moderate gibbosity behind middle; anterior margin completely beaded, basal margin smooth; setiferous punctures identical to those on clypeus, rarely confluent. Scutellum triangular, glabrous; midline weakly raised; punctures identical to those on pronotum. Prosternal process tongue-like, slightly raised apically. Elytra: Discal surface densely rugopunctate; sutural costa gradually broadening apically, widest at apical one-third. Abdomen: Pygidium wider than long; discal surface distinctly rugopunctate with setiferous punctures, setae on apical part longer than basal ones. Sternites 1, 2, 5, and 6 with surface densely punctate; sternites 3 and 4 less densely punctate, punctures deep and setiferous, setae short; sternites 5–6 with short setae intermixed with setae 2–8 times longer. Legs: Protibia tridentate. Profemora, mesofemora, and metafemora ( Fig. 19 ) moderately covered with long, robust setae; metafemora slightly broadened anteriorly and posteriorly, weakly convex. Metatibia upper spur reaching basal one-third of second tarsomere. Genitalia: Parameres with upper part strongly curved downwardly and slightly below lower part when viewed laterally ( Fig. 25 ); parameres slender in dorsal view with beak-like process of upper part protrudent laterally ( Fig. 26 ).

Female. Body length 18.7–19.1 mm; width across humeri 9.2–9.5 1 mm. Antennal club shorter in male, subequal to length of antennomeres 3–6 combined. Pronotal disc glabrous except laterally and in front of scutellum. Elytral setae with same distribution pattern as in males.

Diagnosis. Miridiba kuraruana has most setae on pronotum and elytra tiny (shorter than diameter of punctures) making it appear glabrous, resembling M. sinensis . However, M. sinensis can be separated based on antenna with 10 antennomeres (9 antennomeres in M. kuraruana ); dorsal surface completely glabrous (with a few robust, long setae on base of elytra, front of scutellum, and sutural costa in M. kuraruana (indicated by arrow in Fig. 13)); clypeus with apex distinctly bilobed, lobes obtuse ( Fig. 12 ) (moderately bilobed and lobes round ( Fig. 7 ) in M. kuraruana ); metafemora with only a row of robust setae along posterior margin ( Fig. 24 ) (completely covered with setae in M. kuraruana ( Fig 19 )); parameres asymmetrical, not divided into upper and lower parts ( Fig. 39 ) (parameres asymmetrical and not divided into upper and lower parts in M. kuraruana ( Fig. 25 ).

Distribution. Southern Taiwan ( Fig. 43 ).

Chinese name. 墾丁脊頭鰓金龜

Remarks. Miridiba kuraruana has mainly tiny setae (shorter than puncture diameter) on the dorsal surface, which can only be seen using high magnification. The amount of long setae on the dorsal surface varies among specimens, probably due to loss by abrasion.

Figures

FIGURE 43. Distribution map of Miridiba species in Taiwan: Miridiba kuraruana (open circle), Miridiba formosana (open triangle), Miridiba taipei (black diamond), Miridiba sinensis (open square), and Miridiba huesiotoi and Miridiba taoi indicated by arrow, respectively.

FIGURES 1 – 6. Dorsal habitus of male Miridiba species. 1. Miridiba kuraruana; 2. Miridiba huesiotoi, holotype; 3. Miridiba taoi, holotype; 4. Miridiba formosana; 5. Miridiba taipei, holotype; 6. Miridiba sinensis.

FIGURES 7 – 12. Dorsal view of head and upper half of pronotum of male Miridiba species. 7. Miridiba kuraruana; 8. Miridiba huesiotoi, holotype; 9. Miridiba taoi, holotype; 10. Miridiba formosana; 11. Miridiba taipei, holotype; 12. Miridiba sinensis.

FIGURES 19 – 24. Right metafemur of male Miridiba species. 19. Miridiba kuraruana; 20. Miridiba huesiotoi, n. sp.; 21. Miridiba taoi, n. sp.; 22. Miridiba formosana; 23. Miridiba taipei, n. sp.; 24. Miridiba sinensis.

FIGURES 25 – 32. Parameres of Miridiba species (25, 27, 29, 31, lateral view; 26, 28, 30, 32, dorsal view). 25 – 26. Miridiba kuraruana; 27 – 28. Miridiba huesiotoi; 29 – 30. Miridiba taoi; 31 – 32. Miridiba formosana. Scale bar = 1.0 mm.

FIGURES 33 – 40. Parameres of Miridiba species (33, 35, 37, 39, lateral view; 34, 36, 38, 40, dorsal view). 33 – 34. Miridiba taipei; 35 – 36. Miridiba trichophora; 37 – 38. Miridiba hirsute; 39 – 40. Miridiba sinensis. Scale bar = 1.0 mm.