Amithao metallicus ( Janson, 1885 )

Ratcliffe, Brett C., 2013, A Revision Of The Neotropical Genus Amithao Thomson, 1878 (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini), The Coleopterists Bulletin 67 (3), pp. 265-292 : 284-285

Amithao metallicus ( Janson, 1885) ( Figs. 49–53 )

Desicasta metallica Janson 1885: 146 (original combination). Lectotype male (Ratclffe 2004) at RMNH, examined. Type locality: “ Costa Rica.”

Description. Length 26.0–32.0 mm; width across humeri 14.6–17.2 mm. Color of pronotum

and elytra dark reddish brown to black (elytra often lighter in color than pronotum), with weak metallic green sheen, shiny. Femora and coxae dark reddish brown. Mesepimeron and metaventrites 1–4 on posterolateral corner each with or without cretaceous spot. Pygidium in each basal angle with or without large, cretaceous spot. Head: Lateral margins weakly elevated. Frons and base of clypeus longitudinally tumescent at middle. Surface densely to confluently punctate; punctures mostly large, minutely setigerous (when not abraded away); setae moderately dense, tawny. Clypeus with apex deeply bilobed ( Fig. 49 ), reflexed. Eyes large, interocular width equals 3.5–3.7 transverse eye diameters in both sexes. Antenna with 10 antennomeres, club distinctly longer than antennomeres 2–7 in males, slightly longer than antennomeres 2–7 in females. Pronotum: Surface with punctures moderately dense, moderate to large, punctures becoming larger and denser on lateral thirds. Lateral margin with thick bead. Elytra: Surface moderately densely punctate, with 2 nearly obsolete, elevated, parallel costae terminating at prominent apical umbone; punctures moderate to large, moderately dense, becoming larger and denser laterally, in distinct rows on disc. Apices behind apical umbone usually rugulose. Apices at suture acutely produced. Pygidium: Surface concentrically strigose, glabrous in males, setigerous in females; setae dense, short, black. In lateral view, profile weakly convex in both sexes. Venter: Setae in males tawny, black in females. Mesometasternal process distinctly attenuate and protuberant in lateral view ( Fig. 51 ), apex broadly rounded in ventral view. Abdominal ventrites in both sexes nearly smooth in central third; lateral thirds with moderate to large, sparse to moderately dense punctures. Legs: Protibia slender in males, with 2 lateral teeth. Protibia in females broader, strongly tridentate, teeth subequally spaced. Parameres ( Figs. 52–53 ): Form subrectangular, apices rounded and each with distinct, sharp spur laterally.

Distribution. Amithao metallicus is known from the mountains of Costa Rica and Panama. There is one old specimen at FMNH labeled British Guiana ( Guyana), but I am discounting that record as erroneous. Fabrice Lavalette has conducted extensive studies on the Cetoniinae of nearby French Guiana and has never encountered Amithao species there (personal communication to BCR, February 2013).

Locality Records. 122 specimens from BCRC, BMNH, CASC, CNCI, DEIC, FMNH, HAHC, INBC, MCZC, MGFT, MNHN, RMNH, USNM, WBWC, WSUC, ZMHU, ZSMC. COSTA RICA (95): ALAJUELA (6) : Cariblanco, Río San Lorencito (5 km N Colonia Palmareña). CARTAGO (42) : Estación Quebrada Segundo, La Estrella, Río Grande de Orosi. GUANACASTE (7) : Carrillo. HEREDIA (10) : Pozo Azul, Parque Nacional Braulio Carrillo, Sarapiqui, Virgen del Socorro. PUNTARENAS (12) : Estación Pittier (4.2 km SW del Cerro Gemelo), Guacimal, Monteverde. SAN JOSÉ (3) : Bebedero, Santa Elena. NO DATA (15) . PANAMA (22): BOCAS DEL TORO (1) : Continental Divide near Fortuna. CHIRIQUÍ (19) : Fortuna Dam, Fortuna Dam (7 km SE), Los Planes (7 km N), Puerto Armuelles, No data. COCLÉ (1) : El Cope. NO DATA (1) . NO DATA (5) .

Temporal Distribution. January (2), May (3), June (9), July (22), August (3), September (7), October (12), November (8).

Diagnosis. Amithao metallicus is distinguished by the unique combination of brownish to black elytra (usually with a greenish sheen), dark reddish brown femora and coxae, and often with cretaceous spots on the posterolateral corners of abdominal ventrites 1–4 and a spot in the basal angel of the pygidium.

Nomenclature. Blackwelder (1944) and Krajcik (1998), both following Schenkling’ s (1921) catalog, listed the epithet insigne Bourgoin (1912) as a presumed junior synonym of “ A. metallicum .” Bourgoin, however, was simply describing a small female of Chiriquiba insignis Janson and did not propose a new taxon. Why Schenkling (1921) chose to place insigne with Amithao metallicus is unknown.

Natural History. Specimens have been collected in ripe banana traps at elevations of 900–1,750 m (label data).

Figures

Figs. 49–51. Amithao metallicus. 49) Dorsal view; 50) Ventral view; 51) Lateral view.

Figs. 52–53. Amithao metallicus, parameres. 52) Dorsal view; 53) Lateral view.