Megistophylla xitoui Li & Wang

Li, Chun-Lin, Yang, Ping-Shih & Wang, Chuan-Chan, 2016, Two new species of Megistophylla Burmeister (Coleoptera: Scarabaeidae: Melolonthinae) from Taiwan, with notes on the genus, Zootaxa 4126 (2), pp. 240-250 : 246-249

Megistophylla xitoui Li & Wang , new species

Figs. 2 , 5–6 , 8 , 11–12 .

Holotype male ( Fig. 2 ). Body length 18.5 mm; width across humeri 8.8 mm. Dorsal color blackish brown; venter and legs moderately shiny. Basal antennomeres reddish brown, antennal clubs blackish brown. Dorsum overall setiferous; setae tiny (high magnification for observation required); setae on disc of pronotum and elytra far smaller than diameter of puncture with exception of a row of long, sparse setae at base of head, anterior and posterior margins of pronotum, base of elytra, and scutellum, respectively; long setae brown in color with length 1–7 times longer than diameter of puncture; long setae varied in appearance. Head: Surface densely rugopunctate, puncture large. Clypeus ( Fig. 5 ) with apex distinctly bilobed, anterior margin moderately reflexed, narrowed at base. Clypeofrontal suture clearly defined. Frons moderately raised. Basal carina slightly crescent, strongly raised. Antenna with 10 antennomeres, antennal club with 6 antennomeres, length of club subequal to basal antennomeres 1-4 combined, first antennomere of club slightly shorter than remaining antennomeres of club; fourth basal antennomere greatly enlarged. Thorax: Pronotum widest at middle, anterolateral angles ( Fig. 5 ) strongly protuberant with basolateral angles obtuse, basal half of lateral margin coarsely serrate; lateral declivities with weak gibbosity at middle; anterior margin completely beaded with basal margin smooth; punctures same as those on clypeus, rarely confluent; punctures unevenly distributed along midline ( Fig. 6 ). Scutellum triangular in shape, with a puncture bearing a long seta ( Fig. 6 ). Prosternal process flat, weakly bilobed in shape. Elytra: Discal surface densely rugopunctate, densely confluent at sides of suture; sutural costa gradually broadening apically, densely punctate at margins of costa, rugopunctures strongly and transversally developed over sutural costa, costa becoming flat at apex. Abdomen: Pygidium wider than long; surface with setiferous punctures in uneven distribution, tiny setae same as those of elytral disc. Sternites 1–2, 5–6 with surface densely punctate; sternites 3–4 with sparser setiferous punctures; setae on sternites 3–4 tiny, intermixed on sternites 5–6 with much longer setae. Legs: Protibia tridentate. Protarsomeres 2–3 ( Fig. 8 ) with setae sparsely distributed at apices. Surface of profemora and mesofemora moderately distributed with hair-like, long setae; setae on metafemora shorter and more robust, metafemora slightly broadened at middle. Metatibia with upper apical spur reaching basal one-third of metatarsomere 2; lower apical spur slightly shorter than upper spur. Genitalia: Parameres in lateral view with central concave area concentrically wrinkled densely, apical upper margin smooth with tip gradually narrowed apically ( Fig. 11 ); upper margin of parameres gradually swollen apically at one-fourth ( Fig. 12 ).

Female. Unknown.

Variation. Body length 17.5–20.9 mm; width across humeri 8.4–9.1 mm.Dorsal body color mainly black, rarely dark reddish brown; pronotum with anterolateral angles moderately to strongly protuberant, punctures rarely evenly distributed; scutellum usually impunctate or with less than 10 punctures, punctures sometimes with long setae; elytral sutural costa sometimes not transversally rugopunctate over costa.

Diagnosis. Megistophylla xitoui is morphologically most close to M. formosana and can be distinguished from the later by its distinctly black body color (mainly rufotestaceous to dark reddish brown in M. formosana ); punctures usually unevenly and sparsely distributed along midline of pronotum (usually evenly and densely distributed in M. formosana ); scutellum usually impunctate or with less than 10 punctures (usually exceeding 10 punctures in M. formosana ); protarsomeres 2–3 with setae sparsely distributed at apices (with dense setae aggregated at apices in M. formosana ) and apical upper margin of parameres smooth with tip gradually narrowed apically (distinctly swollen with tip broadly rounded in M. formosana ).

Type material. Male holotype and 17 male paratypes. The male holotype is pinned and with the following information on the label: “C. Taiwan: Nantou, Bird Watching Trail, Xitou, 120.47E, 23.40N, alt. ca. 1,250m, by FIT, 5/Mar-9/Apr/2013, collr. C. -L. Li”. The holotype is deposited at the National Natural Science Museum, Taichung, Taiwan. Paratypes: Three males with the same data as holotype in CCLI; same locality as holotype, “ 25/ Mar-27/Apr/2014 ” (1 male, CCLI); same locality, “ 7/May-15/Jun/2015 ” (1 male, CCLI); “C. Taiwan: Nantou, Fong Hwan Shan, by FIT, 120.48E, 23.39N, alt. ca. 1,800 m, 10/April-23/May/2013, collr. C.-L. Li” (1 male in ZMHB; 2 males in BMNH; 1 male in MTD; 1 male in TFRI; 1 male in CMNC; 2 males in CCLI); same locality, “ 27/Apr-26/May/2014 ” (1 male in ZNS, 3 males in CCLI).

Distribution. Central Taiwan ( Fig. 13 ).

Etymology. The specific name refers to the type locality, Xitou, a mid-elevated (approximately 1250–1800 m) humid throughout the year valley in central Taiwan.

Chinese name: 溪頭脊頭多鰓金龜

Remarks. This new species is only known from the type locality. The type locality is approximately 15 km south of a M. formosana locality (approximately 600 m in elevation), without any significant geographic barrier between these localities. Interestingly, elevation is probably not an important factor separating these species because M. formosana is found from 600–1440 m, which partly overlaps the known elevation of M. xitoui . More field investigations are needed to see if these species of Megistophylla are sympatric in central Taiwan.

Figures

FIGURE 13. Distribution map of Megistophylla species in Taiwan: Megistophylla formosana (open circle), Megistophylla xitoui (open triangle).

FIGURES 1 – 2. Dorsal habitus of male Megistophylla. 1. Megistophylla formosana new species, holotype; 2. Megistophylla xitoui new species, holotype.

FIGURES 3 – 6. Close view of dorsum of male Megistophylla (3, 5 head and anterior half of pronotum; 4, 6 basal half of pronotum, scutellum. and elytra). 3 – 4. Megistophylla formosana new species; 5 – 6. Megistophylla xitoui new species.

FIGURES 7 – 8. Ventral view of protarsomeres 2 – 3 of Megistophylla. 7. Megistophylla formosana new species; 8. Megistophylla xitoui new species.

FIGURES 9 – 12. Parameres of Megistophylla. (9, 11, lateral view; 10, 12, dorsal view). 9 – 10. Megistophylla formosana new species; 11 – 12. Megistophylla xitoui new species. Scale bar = 1.0 mm.