Epitrichius shinshuingensis Li & Yang

Li, Chun-Lin, Yang, Ping-Shih & Wang, Kuo-Sheng Hsu Chuan-Chan, 2008, A review of the genus Epitrichius Tagawa, with an analysis of the internal sac armature of the male genitalia (Coleoptera: Scarabaeidae: Cetoniinae), Zootaxa 1895, pp. 10-24 : 17-22

Epitrichius shinshuingensis Li & Yang , new species

Figs. 1–7

Holotype male ( Fig. 1). Body oval-elongate, length 22.2 mm; width across humeri 9.5 mm. Body overall metallic reddish cupreous except for elytra, elytral reddish brown with two dull yellow, transverse bands, margins diffused, hardly defined. Dorsum slightly iridescent under microscopic view. Canthi, inner side of protibia and anterior margin of metafemur with dull green reflections. Head: Surface glabrous, rugopunctures lengthwise developed and distributed along sides of gena and eyes, size of punctures becoming gradually smaller anteriorly. Anterior margin of clypeus strongly emarginated medially, bilobed tips protruding and moderately acute with very tiny and sparse punctures marginally. Vertex punctures unevenly distributed. Thorax: Pronotum widest at base, semihexagonal, basolateral angles strongly produced and flare outward, lateral margin well defined, weakly serrate ( Fig. 2 ). Surface glabrous with setigerous punctures adjacent to anteriolateral angles; setae short, slender, whitish yellow; surface with sublateral medial concentration of fine setae observable only under microscope. Median longitudinal stripe a conspicuous, contiguous to impunctate area just in front of scutellum; punctures along sides of median stripe sparse, gradually denser laterally. Scutellum triangular, broader than long, rounded at apex, nearly impunctate only with a few weakly developed lateral punctures. Elytra: Shining and glabrous. Margins of elytral with transverse bands diffused, hardly defined. Disc nearly flat, surface with 3 impunctate carinae between suture and humerus, basal third obsolete, middle carinae raised; intervals with punctures scattered; elytral apex and lateral sides rugose. Abdomen: Propygidium clothed with fringe of long yellowish brown setae reaching basal margin. Pygidial width nearly 1.7 times length medially; rugopunctate in concentrical array when viewed caudally; paramedian tufts consisting of dense, long, yellowish brown setae, a pair of vestigial tubercles located between tufts; pygidial disc rarely with tiny setae. Anterior side with sparse, short setae; marginal ridge well developed, moderately truncate. Mesometasternal process strongly protruding with quadrate apex curved vertically when viewed laterally; variably tufted with golden setae in different arrays; metasternum with weakly impressed, median, longitudinal groove widening posteriorly, setose laterally; median metasternal suture well defined; elevations adjacent to median groove glabrous, impunctate at basal halves with row of long setae laterally. Discal center of metasternum with shorter setae; metepisternum finely and sparsely setose. Sternites 1–4 subequal in width, last sternite with subapex weakly sinuate. Sternites 1–4 with paired submedian tufts of long setae, impunctate centrally; sternite 5 with a semicircular tuft centrally; sternite 6 with sparse punctures unevenly distributed, more densely setose punctures tufted centrally, tuft distinctively smaller then on sternite 5. Sternites 1–6 moderately rugopunctate on submedian to sublateral sides with densely setigenous areas from sternites 1–5 and contiguous to transversely shorter setae of anterior margins of sternites 1–5; lateral tips of sternites 2–4 independently tufted with shorter setae. Legs: Protibia unidentate. Inner tips of procoxae, mesocoxae, and metacoxae densely tufted with long golden setae; anterior sides of profemur transversely ridged medially, weakened apically, setae distributed laterally on basal two-thirds. Mesofemora and metafemora having similar arrays of setae on posterior sides, ventral surface with widely separated rugae; profemora sparsely punctate; discs of all femora with only tiny, scattered setae. Anterior margins of protrochanters and mesotrochanters and posterior margins of mesotrochanters and metatronchanters tufted as on coxa and contiguous with setae of femora. Short setae on inner sides of mesotibiae and metatibiae sparsely distributed. Protarsi and mesotarsomere 5 weakly setose on ventral sides; apical notches of tarsomeres 1–4 tufted with deep-brown setae contiguous to ventrally parallel row of setae, length of setae approximately half of each tarsomere; metatarsomeres 2– 5 ventrally covered with long yellowish brown setae, length of setae subequal to tarsomere; tarsomeres 2–4 fully setose on ventral side and tarsomere 5 with basal two-thirds setose; metatarsomere 1 with shorter deepbrown setae on venter and with longer whitish-yellow setae on apical notch; metatarsi 1.5 times longer than metatibiae; inner spurs of mesotibia and metatibia slightly longer than basal metatarsomeres; mesotarsomeres and metatarsomeres 1–4 subequal in length. Male genitalia: Paramere symmetrical, directed downwardly and basally, apex sharpened, inner margin emarginated medially ( Fig. 3 ); ventral inter-paramere extensions with small, isolated sclerotized plate centrally ( Fig. 4 ). Internal sac well developed, dorsum armed with two sclerotized hooks ( Fig. 5 ), outer major hook distinctively larger than inner minor hook, major hook ( Fig. 6 ) roughly trapezoidal in shape, apical tooth protruding upwardly, minor hook ( Fig. 7 ) cork-shaped with upper and inner edges irregularly serrate.

Female. Unknown.

Diagnosis. This new species has parameres very similar in shape to those of Epitrichius fraterculus . However, E. shinshuingensis is distinguished from all other species in the genus by the following combination of characters: larger in body size, overall body including legs reddish cupreous with distinctive metallic reflections; pronotum widest at base; surface almost glabrous, punctures along sides of median stripe sparse; elytra shining, color reddish brown, margins of transverse bands diffused; abdominal sternites 1–4 with paired submedian tufts of long setae; protarsomere and mesotarsomere 5 weakly setose on ventral sides; inner spurs of mesotibia and metatibia slightly longer than basal metetarsomeres; apex of the parameres sharpened, inner side of parameres slightly swollen basal one-thirds; major hook of internal sac trapezoid and distinctively larger than minor hook.

Variation in the type series is slight. The body size of the single paratype is smaller with its length 19.6 mm and width 8.7 mm. Also, the shape of the elytral transverse bands is less diffused and shorter than the holotype.

Type material. The male holotype is pinned and with the following information on the label: TAIWAN: Ping Tong Co., 21st km., Da Haim logging road, alt. ca 1500m., 17/VIII/ 2004, visiting flowers of Elaceocarpus sylvestris, collr. K.-S. Hsu. The paratype male: same collecting locality as the holotype with different date and collector as on August 10, 2004, by L.-C. Shih. The holotype is deposited at the National Museum of Natural Science, Taichung, Taiwan and the paratype is deposited at the Department of Entomology, National Taiwan University, Taipei, Taiwan.

Distribution. Southern Taiwan ( Fig. 19 ).

Etymology. The specific name refers to the old name of the collecting site, Shinshuigen, which is famous since the early 1910’s for being the type locality of several vascular plants endemic to southern Taiwan.

Remarks. Based on collecting efforts over the past three years, adults of this species appear only for a very short period of time, which makes them very difficult to find. The two type specimens of this new species were collected separately from the flowers of Elaceocarpus sylvestris ( Elaeocarpaceae ) and Prunus phaeosticta (Rosaceae) , two common and non-endemic trees in the broadleaved evergreen forests at low and middle elevations in Taiwan. The occurrence of E. shinshuingensis is seemingly restricted to the southern montane areas of Taiwan which distribution pattern is uncommon for scarab beetles in Taiwan.

Figures

FIGURE 2. Lateral side of pronotum of Epitrichius shinshuingensis, scale bar = 2.0 mm.

FIGURE 19. Geographical distribution of the Epitrichius species: Epitrichius bowringii (open circle), Epitrichius fraterculus and Epitrichius versutus (black square) and Epitrichius shinshuigensis (black triangle).

FIGURES 3 – 7. Male genitalia of Epitrichius shinshuingensis. 3. caudal view, scale bar = 1.0 mm; 4. ventral view, scale = 1.0 mm; 5. parameres with internal sac everted, caudal view, scale bar = 2.0 mm; 6. major hook, scale bar = 0.5 mm; 7. minor hook, scale bar = 0.2 mm. Abbreviations: PM-ext = paramere extensions; BP = basal piece; PM = parameres; IS = internal sac; MiH = minor hook; MaH = major hook.