An extension to the known distribution of Berosus chalcocephalus (Coleoptera: Hydrophilidae) in southern Patagonia

Extensión de la distribución conocida de Berosus chalcocephalus (Coleoptera: Hydrophilidae) en la Patagonia austral

Souza, Martín G.

Laboratorio de Entomología. Departamento de Biodiversidad y Biología Experimental. Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Pabellón II. Ciudad Universitaria. C1428EHA. Buenos Aires, Argentina; e-mail: souza@bg.fcen.uba.ar

ABSTRACT. The known geographic distribution of Berosus chalcocephalus Germain is extended to include the provinces of Chubut and Santa Cruz. This is now the southernmost record of a species of the genus in Argentina.

KEY WORDS. Geographic distribution. Hydrophilidae. Berosus. Patagonia. Argentina.

RESUMEN. Se amplía la distribución conocida de Berosus chalcocephalus Germain para incluir las provincias de Chubut y Santa Cruz. Esta es ahora la cita más austral para una especie del género en la Argentina.

PALABRAS CLAVE. Distribución geográfica. Hydrophilidae. Berosus. Patagonia. Argentina.

The genus Berosus Leach is placed in the tribe Berosini of the family Hydrophilidae (Coleoptera). It comprises small to medium-sized water scavenger beetles that inhabit temporary or permanent freshwater water bodies (small ponds, rain pools, etc.). With over 200 species described so far, this cosmopolitan genus is present in South America with 85 species, 39 of which are represented in Argentina (Oliva et al. , 2002). Geographic distribution of the genus in this country is wide, though mostly restricted to the area North of Colorado River and East of the Andes. Oliva et al. (2002) divide the species present in Argentina in five groups, on the base of their distributional pattern; one of this groups, called “Species in the Pampean region”, includes Berosus adustus Knisch, Berosus alternans Brullé, Berosus bruchianus Knisch, and Berosus chalcocephalus Germain.

Only five species have been recorded to occur in the province of Río Negro, South of Colorado River: Berosus festivus Berg, Berosus pallipes Brullé, B. bruchianus , B. alternans and B. chalcocephalus (Fernández & Bachmann, 1998; Oliva et al. 2002). These are, until now, the southernmost records of the genus in Argentina. Berosus chalcocephalus was previously recorded from the provinces of Buenos Aires, Entre Ríos, Río Negro, Neuquén and Salta; also from Chile, Uruguay and Bolivia (Oliva, 1989; Fernández & Bachmann, 1998; Oliva et al. 2002). New records of B. chalcocephalus in southern Patagonia are herein reported, extending the distributional range of this species by more than 900 km to include the provinces of Chubut and Santa Cruz, and thus becoming this the southernmost record of the genus and this species in Argentina.

Material examined. ARGENTINA. Santa Cruz: “Charco al borde de RN 60 camino al Glaciar Perito Moreno”, 50° 25' 19” S, 72° 40' 48” W, 30-I-2001, Marinone col., 2 females; “Pozón margen derecha del río La Leona bajo puente RN 40”, 50° 09' 30” S, 71° 59' 18” W, 30-I-2001, Marinone col., 17 males, 20 females. Chubut: “A 5 km de Sarmiento, mano al N, camino b. petrificados”, 45° 38' 13” S, 69° 04' 21” W, 3-II-2001, Marinone col., 1 male, 1 female.

Some specimens from all the new localities are deposited in the Museo Argentino de Ciencias Naturales (Buenos Aires).

I am indebted to Lic. M. Cristina Marinone, who collected the material. I am also grateful to Dr. Adriana Oliva for confirming the identity of the specimens and to Dr. Axel O. Bachmann for his valuable comments on the manuscript.

LITERATURE CITED

1. FERNÁNDEZ, L. A. & A. O. BACHMANN. 1998. Hydrophiloidea. In: Morrone, J. J. & S. Coscarón (eds.), Biodiversidad de Artrópodos Argentinos. Una perspectiva biotaxonómica, Ediciones Sur, La Plata, pp. 218-226.         [ Links ]
2. OLIVA, A. 1989. El género Berosus (Coleoptera: Hydrophilidae) en América del Sur. Rev. Mus. Arg. Cs. Nat. , Entomología 6 (4): 57-235.         [ Links ]
3. OLIVA, A., L. A. FERNÁNDEZ & A. O. BACHMANN. 2002. Sinopsis de los Hydrophiloidea Acuáticos de la Argentina (Insecta, Coleoptera). Monogr. Mus. Argentino Cienc. Nat. 2: 1-67.         [ Links ]

Recibido: 10-II-2004
Aceptado: 1-IV-2004