Macrodactylus nobilis Frey, 1963

Arce-Pérez, Roberto & Morón, Miguel Ángel, 2014, New species and records of Macrodactylus Dejean (Coleoptera: Scarabaeidae: Melolonthinae: Macrodactylini) from Bolivia, Zootaxa 3857 (2), pp. 292-300 : 295-296

Macrodactylus nobilis Frey, 1963

( Figs. 5–6 , 14–17 )

Diagnosis. Integument of body, head, pronotum, and scutellum black; inner half of the elytra dark; clypeus, antennae, legs, outer half of the elytra, sternite 6, and pygidium clear yellow. Dorsally with dense whitish yellow setae that covers head and scutellum; pronotum with three wide stripes, elytra with stripe along inner half. Tarsi without rings of white setae. Parameres glabrous.

Redescription. Male: Body length 13.5 mm; humeral width 4 mm. Color: Body black; clypeus, antennae, legs, outer half of elytra, sternite 6, and pygidium clear yellow. Surface: dorsally with dense whitish yellow setae that covers head and scutellum, pronotum with three wide stripes of white setae; elytra with one wide stripe of white setae on inner half; ventral vestiture longer and dispersed. Head: short and wide. Clypeus trapezoidal, reddish yellow; anterior border nearly straight. Antennal club as long as the preceding 5 antennomeres. Maxillary palpus clear yellow. Mentum reddish yellow, long, wide, oval; longitudinally furrowed, with scattered setae on surface. Thorax: Pronotum hexagonal, convex, length 3.25 mm, width 3.25 mm. Prosternal process yellow, very short and wide, hidden in frontal view. Scutellum black, elongate, covered with white setae. Elytra with inner half dark and wide stripe of white setae, yellow outer half is glabrous, with erect long setae at sides of scutellum. Metasternum wide, black; with dense rows of long, reddish-yellow setae between mesocoxae and metacoxae. Abdomen: Sternites 2–5 moderately concave at middle, with 5–6 spine-like, yellow, long setae at each side of midline; length of sternite 5 twice length of sternite 4, apical third glabrous, light yellow; sternite 6 ovate, yellow, with spine-like, long setae. Pygidium elongate, ovate, with medium size setae uniformly distributed on disc; with long, slender setae on apical border. Legs: Profemur with a subtriangular, curved and sharp projection near base. Mesotibia widened toward the apex; with two straight, slightly curved spurs and spine-like setae around apex. Tarsi enlarged, without rings of setae and with long spine-like setae around apex. All tarsal claws long and cleft. Genitalia: Total length 2.50 mm. Parameres short and wide, round-oval, glabrous, fused dorsobasally, with marked internal emargination; apex with rounded tip; length 0.86 mm, width 0.82 ( Figs. 14–16 ).

Female: Body length 13 mm; humeral width 4.2 mm. Similar to males except as follows: Antennal club as long as the preceding 4 antennomeres; pronotum width 3.40 mm, length 2.8 mm, with glabrous lines covered with short setae; sternites 2–5 convex at middle with a lines of spine-like setae at each side of midline. Genital plates long, oval, length 1.28 mm, width 0.54 mm, apex rounded; asymmetrical and external border nearly straight ( Fig. 17 ).

Variation: Body length 12.8–13.5 mm; humeral width 4.0– 4.2 mm. One female with elytra completely yellow.

Material examined: BOLIVIA, La Paz , 3650 m, paratype female ( NHMB). BOLIVIA, Santa Cruz, 16 km NE Mairana , Yunga de Mairana , 18°03'35''S 63°54'38''W, 29-I-1999, 2100–2300 m, Yungas ex. hand collecting, trail, 99-009; F. Génier (99 CMNC, 4 MXAL, 4 IEXA).

Natural history: A large sample was collected in January (107 specimens) on a single unidentified tree in a wet elfin forest located between 2100–2300 m (F. Génier, CMNC, personal communication). The type locality of M. nobilis is “La Paz, 3650 m ”, but probably corresponds to some a site along the road from La Paz to Cochabamba, because the type of vegetation near La Paz is much different from “Yungas” forest. “Los Yungas” is a geographic region located between the northeast of La Paz department and part of Cochabamba and Santa Cruz departments, on mountain slopes between 600 and 2500 m elevation where the hot-humid climate promotes exuberant vegetative growth.

Remarks. Large body size, strongly contrasting colors, and the shape of male and female genitalia, aid in the recognition of this species.

Figures

FIGURES 1 – 6. Macrodactylus megaphyllus: 1) dorsal view, 2) lateral view. Macrodactylus yunganus: 3) dorsal view, 4) lateral view. Macrodactylus nobilis: 5) dorsal view, 6) lateral view.

FIGURES 7 – 17. Diagnostic structures of Macrodactylus megaphyllus: 7) parameres, distal view, 8) parameres, lateral view, 9) basal piece, dorsal view. Macrodactylus yunganus: 10) parameres, distal view, 11) parameres, lateral view, 12) basal piece, dorsal view, 13) female genital plates, ventral view. Macrodactylus nobilis: 14) parameres, distal view, 15) parameres, lateral view, 16) basal piece, dorsal view, 17) female genital plates, ventral view. Scales in mm.