Marmarina tigrina (Gory and Percheron, 1833)

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 : 196-198

Marmarina tigrina (Gory and Percheron, 1833) ( Figs. 29–35 )

Gymnetis tigrina Gory and Percheron 1833: 71 , 349 (original combination). Lectotype male at MHNG, labeled “ Brazil //Gory/Type” and with my red lectotype label. Paralectotype male at MHNG, labeled “Gory/Type/ Coll. Meley ” and with my yellow paralectotype label. Lectotypes designated by Ratcliffe (2004).

Gymnetis albosparsa Blanchard 1847: 193 (synonym). Type not seen. Type locality: “San-Blas (Patagonie).”

Gymnetis touchardi Blanchard 1847: 193 (synonym). Holotype female at MNHN, labeled “Museum Paris/Repub. Argent./Prov. Entrerios/ touchard 1838//type”, examined. Type locality: “Entre-Rios.”

Gymnetis strobeli Burmeister 1866: 576 (synonym). Type not seen. Type locality: “ Cerro del Diamante , 60 leagues south of Mendoza, Argentina.”

Marmarina litorea Schürhoff 1937: 64 (synonym). Lectotype male at NMBC, labeled: “ Brasilien / St. Catharina//Sammlung Schürhoff// Maculinetis litorea m./Type, male symbol/determ. Schürhoff, Berlin” and with my red lectotype label. Lectoallotype female at NMBC, labeled “B. Retiro/1 96//Sammlung Schürhoff// Maculinetis litorea m./Type, male symbol, determ. Schürhoff, Berlin” and with my red lectoallotype label. Paralectotype male at NMBC, labeled “ Brasil, St. Cath./Heyne//Sammlung Schürhoff//co-type” and with my yellow paralectotype label. Paralectotype female at NMBC, labeled “ Brasilien / Porto Alegre//Sammlung Schürhoff/co-type” and with my yellow paralectotype label. Lectotypes designated by Ratcliffe (2004).

Description. Length 12.8–17.5 mm; width across humeri 7.7–11.4 mm. Ground color and punctures dark reddish brown to black, opaque to weakly shiny, with extensive enamel-like or opaque pale yellow (most common) ( Fig. 29 ) to ochre to orange ( Fig. 30 ) to rarely grayish or almost cream white ( Fig. 31 ) marks as follows: Head enamel-like, completely covered except for short, longitudinal, dark line on center of frons and on apical rim of clypeus. Pronotum opaque, completely covered except for slender to thick, broken, dark bands radiating anteriorly from pronotal lobe. Elytra each covered except for transverse or oblique, broken, dark bands ( Figs. 29–31 ). Pygidium completely covered (usually enamellike) except for dark spot either side of midline at base in males, spots occasionally coalescing; females similar to more commonly basal half dark, occasionally entirely dark. Venter of males shiny black with variable, enamel-like pale yellow or ochre marks on mesepimera, metepisterna, metepimera, metasternum, and abdominal sternites; females usually with yellow or ochre marks reduced or almost absent. Metacoxae, meso- and metafemora, and meso- and metatibiae each with enamel-like pale yellow or ochre (rarely grayish or cream white). Colored areas of venter and legs may be variably reduced or absent. Setae of venter and legs black, occasionally ferruginous. Head: Males on frons and clypeus vaguely tumescent at center, punctures usually small, sparsely to moderately dense; females with punctures larger, denser, especially on dark areas. Clypeal apex slightly thickened, weakly emarginate, slightly reflexed. Interocular width equals 4.0 transverse eye diameters in males and 5.0 in females. Antenna with 10 antennomeres, club subequal in length to entire stem in males, slightly shorter in females. Pronotum: Surface with small, sparse punctures on colored areas, punctures larger, usually denser on darker areas. Lateral margins weakly emarginate or evenly arcuate between middle and basal angle, with slender marginal line not reaching basal angle. Elytra: Surface similar to that of pronotum. Sutural costa and usually costae on disc each elevated on apical halves. Apices at suture subquadrate. Pygidium: Dark areas in both sexes with sparse, transversely vermiform punctures or densely, transversely rugulose and with minute, black or ferruginous setae in pristine specimens; surface on colored areas usually with small, round (occasionally kidney-shaped) punctures. 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 mesometasternal process. Mesometasternal process, in lateral view, long, thick, projecting obliquely away from ventral axis of body, apex broadly rounded ( Fig. 32 ); in ventral view, sides tapering to broadly rounded apex ( Fig. 33 ). Abdominal sternites 1–6 of both sexes with small, sparse punctures on colored areas and moderately large, sparse punctures on dark areas, near lateral margins. Legs: Protibiae of males with

strong tooth at apex. Females similar, occasionally with weak second tooth behind apical tooth. Parameres: In caudal view, form elongate, subrectangular, apices blunt and subacute on apicolateral angle ( Figs. 34–35 ).

Distribution. Marmarina tigrina occurs in southern South America in Argentina, Brazil, Paraguay, and Uruguay. The northernmost record is in Chapada Diamantina, Bahia, Brazil, and the westernmost record is Mendoza, Argentina. There are erroneous records for single specimens each from Bolivia, Costa Rica, Colombia, and Venezuela (all specimens without specific locality data).

Locality Records. 604 specimens from BCRC, BMNH, CASC, CMNC, CMNH, CNCI, CUIC, DEIC, FIOC, FMNH, LACM, MCZC, MHNG, MLPA, MLUH, MNHN, MZSP, NMBC, RMNH, SEAB, SLTC, UCCC, UNSM, USNM, WBWC, ZMHU, and ZSMC. Some data from Bruch (1911), Monné (1969), Viana and Williner (1981), and Di Iorio (2013). ARGENTINA (251): BUENOS AIRES (34): Bahía Blanca, Buenos Aires, Carmen de Patagones, La Plata, La Valleja (Route 8, km 134), Puerto Belgrano, San Blas, Sierra de la Ventana, Villarino. CATAMARCA (5): Catamarca, Famabalastro, La Ciénaga (Belén), Santa María. CHACO (1): No data. CHUBUT (2): Puerto Madryn, No data. CÓRDOBA (84): Alta Gracia, Arguello, Capilla del Monte, Carlos Paz, Colón, Concordia, Córdoba, Cosquín, Dean Funes (24 km S), Diqucito, El Sauce, La Falda, La Paz; La Granja, Las Rosas, Los Cocos, Los Molinos, Los Reartes, Mina Clavero, Punilla, San Javier, San Roque, Santa Maria, Santa Rosa, Tanti, Valle Hermoso, Villa Cabrera, Villa María, Yacanto de Calamuchita. CORRIENTES (8): Estancia Buena Vista, Goya, Santo Tomé, No data. ENTRE RÍOS (4): Crespo, Liebig, Paraná, No data. LA PAMPA (5): General Pico, Monte Nievas, Toay, No data. LA RIOJA (1): Patiquía. MENDOZA (2): Cerro del Diamante (60 leagues S. Mendoza), Mendoza. MISIONES (8): Pindapoy, No data. NEUQUÉN (1): Junin de los Andes. RIÓ NEGRO (23): Cipoletti, Lamarque, Meseta de Somuncurá, Valcheta, Viedma. SALTA (8): Rosario de Lerma, Salta. SAN LUIS (5): Carpintería, El Volcán, Merlo, San Luis, Villa Elena. SANTA CRUZ (1): Cañadón los Leones, SANTA FE (14): Carcarañá, Estancia La Noria (Río San Javier), Piquete, San Jerónimo, No data. SANTIAGO DEL ESTERO (26): Choco region, Icano, Santiago del Estero. TUCUMÁN (4): Tucumán, No data. NO DATA (11). BRAZIL (87): BAHIA (3): Chapada Diamantina. GOIÁS (7): Jatahy, Mineiros, Rio Verde. MINAS GERAIS (1): No data. RIO GRANDE DO SUL (26): Bom Ritiro, Pelotas, Porto Alegre, São Leopoldo, No data. SANTA CATARINA (21): No data. NO DATA (29). PARAGUAY (41): ALTO PARANÁ (2): Tacarubucu, No dta. AMAMBAY (2): No data. CAAGUAZÚ (1): No data. ITAPÚA (9): Bella Vista, No data. PARAGUARÍ (7): Paraguarí, Sapucai. NO DATA (20). URUGUAY (159): ARTIGAS (1): Arroya de la Invernada. CANELONES (4): Canelones. CERRO LARGO (1): Cerro Valeriano. COLONIA (2): Carmelo. FLORIDA (4): Chamiza, Mendoza. LAVAJELLA (4): No data. MALDONADO (3): Piriápolis, Sierra de las Ánimas. MONTEVIDEO (10): Montevideo. PAYSANDÚ (20) Paysandu. SORIANO (1): Puntas del Arenal. TACUAREMBÓ (3): Tacuarembó. TREINTA Y TRES (2): Ruta 8 (km 115), Santa Clara de Olimar. NO DATA (11). NO DATA (66).

Temporal Distribution. January (44), February (59), March (5), April (2), May (1), October (1), November (12), December (16). Most specimens are old and lack date of capture information.

Diagnosis. Marmarina tigrina is identical with M. argentina except for the distinctive form of the mesometasternal process of both species ( Figs. 32–33 versus Figs. 3–4 ). The large, thick, obliquely projecting process in M. tigrina easily contrasts with the short, blunt, subparallel process in M. argentina . The form of the mesometasternal process is important in the Gymnetini , and it is consistently expressed within any given species. Try as I might, I could find no other characters that would help to separate these two species, especially since each varies so much in color, pattern, and surface sculpturing.

The orange-colored morphotype of M. tigrina is remarkably similar to Gymnetis hieroglyphica (Vigors) in color and pattern. Marmarina tigrina has apical angles of the clypeus noticeably narrowed and rounded, whereas those angles in G. hieroglyphica are nearly right angled, thus giving the apex of the clypeus a broader, subtruncate appearance. In addition, the pygidium and abdominal sternites in M. tigrina have the genus-typical, enameled yellow or orange color (often reduced in females), but the pygidium and sternites in G. hieroglyphica are black with small, opaque, orange flecks on the lateral margins of the sternites.

Nomenclature. Marmarina tigrina shows great variation in color that ranges from light to dark sulfur yellow to orange to grey to nearly black, and also in the expression of its pronotal and elytral patterns that vary from sparse to dense. As a consequence, several names have been proposed for these variants, none of which constitute different species. Blanchard (1847) said of his G. touchardi that it was probably just a variety of G. tigrina , and of his G. albosparsa that it was probably just a smaller variety of G. touchardi and G. tigrina . These two Blanchard names are synonyms. Krajcik (1998) listed G. punctata Blanchard, 1850 as a junior synonym of G. tigrina , but the one line descriptor of this supposedly Mexican species in Blanchard (1850) cannot be reliably assigned to G. tigrina . Schürhoff (1937) correctly placed G. punctata as a “subspecies” of G. (now Hologymnetis ) cinerea , and after examining the type in Paris, I confirmed that it is a junior synonym of H. cinerea (Ratcliffe and Deloya 1992) .

Burmeister (1866) noted there are specimens of G. tigrina that are totally black. In describing G. strobeli, Burmeister (1866) stated it was exactly like G. tigrina , but its black areas were lustrous and shiny as opposed to opaque. This character state is occasionally seen, but it does not constitute a different species. Marmarina litorea Schürhoff is simply an ochre or orange morphotype as opposed to the more commonly encountered yellow form, and it does not represent a different species.

Natural History. Adults have been collected in accumulated vegetation in the nests of Acromyrmex lundi (Guérin-Méneville) ( Berg 1890) and in the fungal nests of Acromyrmex species in Argentina (label data and A. Martínez, personal communication, April 1979). Navarrete-Heredia (2001), citing Bruch (1929) and Weber (1972), indicated larvae were found in the external accumulated debris of the nests of A. lundi and Acromyrmex lobicornis (Emery) in Argentina. Monné (1969) described the third instar from Trienta y Tres, Uruguay that was found in the nest of Acromyrmex species.

Di Iorio (2014) noted that M. tigrina adults are essentially floricolous and have been collected from the flowers of Eryngium species (Apiaceae) . Adult beetles were seldom found on other food sources, although they were observed feeding on slime fluxes, chewing the stem of Baccharis incisa Hooker and Arnott (Asteraceae) , and collected in banana-baited traps ( Di Iorio 2014). Burrowing owls, Speotyto cunicularia partridgei Olrog ( Aves: Strigidae ), feed on adults, and numerous beetle remains have been found in regurgitated pellets from owl nests ( Di Iorio 2014).

Figures

Figs. 29–31. Marmarina tigrina, habitus showing variation.

Figs. 32–35. Marmarina tigrina. 32–33) Mesometasternal process, lateral and ventral views; 34–35) Parameres.

Figs. 3–6. Marmarina argentina. 3–4) Mesometasternal process, lateral and ventral views; 5–6) Parameres.