Miridiba (Miridiba) formosana ( Moser, 1909 )

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 : 528-530

Miridiba (Miridiba) formosana ( Moser, 1909)

Figs. 4 , 10 , 16, 22, 31, 32

Holotrichia formosana Moser, 1909: 470 (Type locality: Manto Distr. (presently Nantou City, Nantou). Lectotype in ZMHB, not examined).

Holotrichia (Pledina) formosana: Chang 1964: 149 (new subgeneric combination, key).

Neodontocnema formosana: Arrow 1948: 51 (new generic combination).

Miridiba (Miridiba) formosana: Nomura 1977: 89 (new generic combination, key, collecting records, figures, drawings); Smetana & Král 2006: 222 (catalog); Coca-Abia 2008: 679 (lectotype designated, figures, diagnosis, remarks, key).

Specimens examined. TAIWAN. Ilan County: Fushan Botanical Garden, 20/V/1993, C.-L. Li (1 male, CCLI). Taoyuan County: Fuhsin, 6–8/VI/1972, M.-L. Juang (2 females, NMNS); Balin, 28/V/1988, C.-K. Yu (2 females, CCLI); Hou Tzi Hu, 4–5/V/1991, I.-S. Hsu (1 male, 2 females, CCLI); Hou Tzi Hu, 19–22/V/1991, I.-S. Hsu (1 male, CCLI); Hou Tzi Hu, 26/V/1991, I.-S. Hsu (1 male, CCLI); San Ming, 27/V/1992, C.-C. Chen (4 males, 3 females, CCLI). Taipei City: Yangmingshan, 26/V/1972, B.-S. Chang (1 female, NMNS); Er Tzi Pin (Ba La Ka Motorway), 24/V/1992, C.-L. Li (1 male, 1 female, CCLI); Taipei Botanical Garden, 26/IV/1960 (2 females, TFRI); Mucha, 20/IV/2005 (1 female, CCLI); Chinan temple, 3/V/1992, C.-L. Li (3 males, 2 females, CCLI); Jinmei, 9/VI/1988, C.-L. Li (1 male, CCLI). New Taipei City (formerly Taipei County): Wulai, Hsinsien, 30/VII/ 2011, R.-F. Hsieh, by light trap (1 male, CCLI); Kwan In Shan, 2/VI/1993, I.-S. Hsu (2 males, CCLI). Hsinchu County: Pao Shan, 20-22/V/1993, C.-C. Chen (2 females, CCLI). Nantou County: Lienhuachih, 10/V-12/VII/2004, C.-S. Lin & W.-T. Yang, by Malaise trap (KCN) (1 male, NMNS). Kaoshiung County: Maolin, 12/V/1991, C.-K. Yu (1 male, CCLI).

Redescription. Male ( Fig. 4 ). Body length 17.9–21.3 mm; width across humeri 8.7–9.7 mm. Color dark reddish brown to rufotestaceous on head and pronotum; reddish brown to yellowish brown on elytra, venter, and legs; moderately shiny. Antennae yellowish brown to reddish brown. Dorsum overall covered with brownish pale setae; setae thin, soft, semierect, moderately long; setae on head longer than setae on pronotum and scutellum; setae on elytra slightly thicker compared to those on pronotum with a row of hair-like setae at base 3–5 times longer than those on disc (Fig. 16). Head: Surface densely rugopunctate; punctures large, each bearing an erect seta. Clypeus ( Fig. 10 ) with apex weakly bilobed and reflexed, narrowed at base. Clypeofrontal suture clearly defined. Basal carina straight, distinctly raised. Antenna with 9 antennomeres, club subequal to length of antennomeres 2–6 combined. Thorax: Pronotum widest at middle, anterolateral angles moderately protuberant ( Fig. 10 ), basolateral angles obtuse, lateral margin coarsely serrate, moderately reflexed; lateral declivities with weak gibbosity behind middle in larger males; anterior margin completely beaded, basal margin smooth; setiferous punctures shallow and smaller than those on clypeus, rarely confluent. Scutellum triangular, flat; punctures identical to those on pronotum. Prosternal process tongue-like, raised apically. 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 setae on base. Sternites 1, 2, 5, and 6 with surface densely punctate; sternites 3 and 4 less densely punctate, punctures setiferous, setae short; sternites 5–6 with setae intermixed with setae 2–10 times longer. Legs: Protibia tridentate. Profemora, mesofemora, and metafemora ( Fig. 22 ) sparsely covered with hair-like, long setae; metafemora broadened anteriorly and posteriorly, slightly convex. Metatibia upper apical spur reaching basal one-third of second tarsomere. Genitalia: Parameres with upper part strongly curved downwardly above lower part when viewed laterally (indicated by twoheaded arrow in Fig. 31 ); parameres slender in dorsal view ( Fig. 32 ).

Female. Body length 16.5–22.3mm; width across humeri 7.6–10.1 mm. Antennal club shorter than in male, subequal to length of antennomeres 3–6 combined. Setae on elytral disc short, subequal to diameter of puncture, except for setae at base.

Diagnosis. See diagnosis of M. huesiotoi for comparison of species.

Distribution. Taiwan. Eastern China: Liaoning ( Smetana & Král 2006), Hebei, Jiangsu, Zhejian, Jiangxi, Guanxi ( Chang 1964).

Chinese name. 蓬萊脊頭鰓金龜

Remarks. Miridiba formosana is common in Taiwan and sympatric with M. sinensis but is absent from the southernmost part of Taiwan. The temporal distribution of M. formosana is from the end of April to August.

Figures

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.