Miridiba (Miridiba) taoi Li & Wang

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 : 528

Miridiba (Miridiba) taoi Li & Wang , new species

Figs. 3 , 9 , 15, 21, 29, 30

Males ( Fig. 3 ). Body length 14.7–16.6 mm; width across humeri 6.9–7.9 mm. Color dark reddish brown on head and pronotum; reddish brown to dark reddish brown on elytra, venter, and legs; weakly shiny. Antenna brown. Dorsum completely covered with brown setae; setae thin, soft, semierect, moderately long; setae on head longest, setae on disc of pronotum subequal in length with longer setae laterally; base of elytra and sutural costa with setae 2–4 times longer than those on disc; scutellum with shortest and thinnest setae (Fig. 15). Head: Surface densely rugopunctate; punctures large, each bearing a semierect seta. Clypeus ( Fig. 9 ) with apex moderately bilobed and reflexed, slightly narrowing at base. Clypeofrontal suture clearly defined. Basal carina straight, weakly raised. Antenna with 9 antennomeres, club subequal to length of antennomeres 2–6 combined. Thorax: Pronotum widest at middle, anterolateral angles ( Fig. 9 ) slightly protuberant, basolateral angles obtuse, lateral margin coarsely serrate, moderately reflexed; lateral declivities without gibbosity; anterior margin completely beaded, basal margin beaded at center; setiferous punctures as large as those on head, densely set, some confluent. Scutellum triangular, flat; punctures smaller than those on pronotum. Prosternal process tongue-like, tip slightly raised. Elytra: Discal surface densely rugopunctate; sutural costa gradually broadening apically, widest at apical one-third. Abdomen: Pygidium wider than long; disc with densely setiferous punctures, setae on apical part longer than basal setae. Sternites 1–4 moderately densely to sparsely punctate; sternites 5–6 with densely set, setiferous punctures; setae short, intermixed with setae 2–6 times longer. Legs: Protibia tridentate. Profemora, mesofemora, and metafemora ( Fig. 21 ) moderately covered with hair-like, long setae; metafemora slightly broadened anteriorly and posteriorly, slightly convex. Metatibia upper spur reaching basal one-third of second tarsomere. Genitalia: Parameres with upper part gradually curved downwardly below lower part when viewed laterally ( Fig. 29 ); parameres widened in dorsal view ( Fig. 30 ).

Female. Unknown.

Diagnosis. Miridiba taoi shares with M. taipei a body smaller than any other Taiwanese species in the genus. However, it can be easily separated from M. taipei by the length of setae on the pronotum and elytra distinctly shorter ( Figs. 3 , 9 ) (hair-like, long setae in M. taipei ( Figs. 5 , 11 )); setae on clypeus and scutellum (Fig. 15) (glabrous in M. taipei (Fig. 17)); metafemora slightly broadened anteriorly and posteriorly ( Fig. 21 ) (metafemora slender in M. taipei ( Fig. 23 ); and upper part of parameres abruptly curved downwardly ( Fig. 29 ) (evenly curved downwardly in M. taipei ( Fig. 33 ).

Type material. The male holotype is pinned and with the following information on the label: Taiwan: Tai Tung Co., Lan Yu Is., 23-25/III/ 1992, collr. C. -L. Li. The holotype is deposited in NMNS. Two male paratypes: one with same data as the holotype in the Natural History Museum, London, United Kingdom and the other with collecting data labeled as: Taiwan Taitung, Lanyu Hangtoushan, IV/24/1997, M. M.Yang, Sweeping Net, deposited in NMNS.

Distribution. Southeastern Taiwan (Lanyu Island) ( Fig. 43 ).

Etymology. The specific name refers to the Tao tribe, an aboriginal people native to Lanyu Island, which is the type locality of the new species.

Chinese name. 達悟脊頭鰓金龜

Remarks. This new species inhabits Lanyu Island located some 85 km off the southeastern coast of Taiwan ( Fig. 43 ) as the only representative of the genus found on this small island.

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.