Marmarina Kirby, 1827

Ratcliffe, Brett C., 2015, A Review of the Neotropical GenusMarmarinaKirby, 1827 (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini), with Description of a New Species from Argentina, The Coleopterists Bulletin 69 (2), pp. 183-201 : 185-186

Marmarina Kirby, 1827

Marmarina Kirby 1827: 153 . Type species: Cetonia maculosa Olivier 1789: 85 (designated by Martínez 1949).

Maculinetis Schürhoff 1937: 56 (nomen nudum).

Description. Form elongate, subparallel, slen- der to robust, slightly dorso-ventrally flattened. Length 11.4–20.0 mm. Ground color on dorsum varies from dark reddish brown or black to yellowish brown or orange, opaque to weakly shiny, with extensive, opaque, pale yellow to ochre to orange to rarely grayish or reddish brown or almost cream white to black marks; marks in form of transverse or oblique bands or large, round spots on pronotum and elytra. Venter and legs vary from shiny black with variable, enamel-like pale yellow or ochre marks to completely enameled with dark punctures. Setae of venter and legs black or pale, rarely ferruginous. Head: Frons and clypeus vaguely tumescent at center or not, punctate. Clypeal apex slightly thickened, slightly reflexed, weakly emarginate. Antenna with 10 antennomeres, club subequal in length or slightly shorter than entire stem in males, slightly shorter in females. Pronotum: Surface with small to large, sparse to dense punctures. Elytra: Surface similar to that of pronotum. Sutural costa and sometimes costa on disc each elevated on apical halves. Apices at suture subquadrate. Pygidium: Surface with sparse to dense, crescent-shaped to transversely vermiform punctures or densely, transversely rugulose and with short, black or pale setae in pristine specimens. In lateral view, surface weakly convex in both sexes. Venter: Metasternum with moderate to large, sparse to usually dense, round to crescent-shaped, setigerous punctures either side of impunctate or sparsely punctate mesometasternal process. Mesometasternal process, in lateral view, short (not extending past apices of mesocoxae) to slightly longer; if longer, projecting slightly obliquely away from ventral axis of body, apex broadly rounded to subquadrate; in ventral view, sides taper to rounded apex. Abdominal sternites 1–5 of both sexes with small to moderately large, round to crescent-shaped punctures on lateral margins; sternite 6 usually with denser punctures. Legs: Protibiae with strong tooth at apex, lacking additional external teeth except in Marmarina parvula Ratcliffe , new species. Parameres: In caudal view, form elongate, subrectangular, apices blunt and with subacute or acute apicolateral angles.

Distribution. Species of Marmarina are known from southern Mexico to Argentina.

Diagnosis. The characters of most taxonomic value for distinguishing Marmarina species from other New World gymnetine genera are: lack of armature on the frons and clypeus (armature present in Chiriquibia Bates , Tiarocera Burmeister , Allorrhina Burmeister , and Cotinis Burmeister ); clypeus weakly reflexed, slightly emarginate (deeply emarginate in Hadrosticta Kraatz , Amithao Thomson , Desicasta Thomson , and Guatemalica Neervoort van de Poll ); prosternum with spur (spur absent in Hologymnetis Martínez ); antennal scape not elongated (scape as long as next four antennomeres combined in Heterocotinis Martínez ); dorsal coloring opaque with variable pattern of speckles, spots, or obliquely transverse bands on pronotum and elytra (pronotum and/or elytra with cretaceous bands or spots in Gymnetina Casey); dorsal surface lacking scales or dense setae (scales present in Balsameda Thomson , setae present in Hoplopygothrix Schürhoff and Neocorvicoana Ratcliffe and Micó ); venter with weakly shiny, enamel-like coloring on shiny black ground color; mesometasternal process short and blunt, not or only slightly longer than apices of mesocoxae and subparallel to ventral axis of body or projecting slightly obliquely downwards (mesometasternal process large, subquadrate, strongly declivous in Gymnetis MacLeay ); protibiae with apical tooth, occasionally with swelling behind apical tooth suggestive of a second tooth (that of M. parvula is weakly tridentate); metafemorae not enlarged (enlarged in Blaesia Burmeister , slightly enlarged in Halffterinetis Morón and Nogueira ); posterolateral corner of metacoxa rounded to subquadrate, not acutely produced backwards; and apices of elytra at the suture rounded (acute or spinose in Hoplopyga Thomson ).

Like most other gymnetines, males are distinguished from females by having both spurs on the apex of the metatibia acute (bluntly rounded in females) and with the abdominal sternites usually distinctly concave (planar or tumescent in females).

Natural History. Adults of Marmarina species are diurnal. Morón et al. (1997) reported adults have been collected from mature tropical fruits but rarely from rotting fruit traps, and that the larvae feed on organic matter beneath rotting logs or in the debris of ant nests of Acromyrmex species ( Hymenoptera : Formicidae ).