Two new records of ceratocanthinae from northeastern Argentina (Coleoptera: Scarabaeoidea, Hybosoridae)

Dos nuevas citas de ceratocanthinae para el nordeste Argentino (Coleoptera: Scarabaeoidea, Hybosoridae)

SCIENTIFIC NOTE

Two new records of ceratocanthinae from northeastern Argentina (Coleoptera: Scarabaeoidea, Hybosoridae)

Dos nuevas citas de ceratocanthinae para el nordeste Argentino (Coleoptera: Scarabaeoidea, Hybosoridae)

Alberto Ballerio^I; Giuseppe M. Carpaneto^II

^IViale Venezia 45, 25123 Brescia, Italy; [e-mail]

^IIDipartimento di Biologia, Università degli Studi "Roma Tre", Viale Guglielmo Marconi, 446, 00146 Roma, Italy; [e-mail]

ABSTRACT

Germarostes (Haroldostes) rugiceps (Germar) and Germarostes (Haroldostes) diffundus (Petrovitz) (Ceratocanthinae) are recorded for the first time for Argentina from Misiones and Corrientes, respectively. This brings to thirteen the total number of the Ceratocanthinae species recorded for Argentina up to now. Some remarks on the type series of G. diffundus and on the collecting circumstances of the Argentine specimens in here discussed are included.

Key words:Germarostes (Haroldostes) rugiceps, Germarostes (Haroldostes) diffundus, Misiones, Corrientes, morphology

RESUMEN

Germarostes (Haroldostes) rugiceps (Germar) y Germarostes (Haroldostes) diffundus (Petrovitz) (Ceratocanthinae) son registrados por primera vez para Argentina, para Misiones y Corrientes respectivamente. Con estos registros se suman a un total de trece las especies de Ceratocanthinae registradas para Argentina hasta el momento. Se incluyen comentarios sobre la serie tipo de G. diffundus y las circunstancias en las que fueron colectados los especímenes de Argentina.

Palabras clave:Germarostes (Haroldostes) rugiceps, Germarostes (Haroldostes) diffundus, Misiones, Corrientes, morfologia

Eleven species of Ceratocanthinae have been recorded until now from Argentina: Germarostes (Germarostes) aphodioides (Illiger), Germarostes (Germarostes) argentinus (Ohaus), Germarostes (Germarostes) macleayi (Perty), Germarostes (Germarostes) plicatus (Erichson & Germar), Germarostes (Germarostes) posticus (Germar), Germarostes (Germarostes) punctulatus (Ohaus), Germarostes (Germarostes) pusillus (Laporte de Castelnau) (doubtful record by Ohaus), Germarostes (Haroldostes) hamiger (Ohaus), Ceratocanthus fuscoviridis (Ohaus), Ceratocanthus politus (Erichson & Germar) and Astaenomoechus hospes (Wasmann) (Ohaus 1910, 1911, Paulian 1982, Howden & Gill 2000, Ocampo & Ballerio 2006). The aim of this paper is to provide new records concerning two species of Germarostes new to Argentina: the first was found by one of us (A B) among unidentified material in his collection; the second one was collected during a recent faunistic survey carried out by the other of us (G M C) in NE Argentina.

Germarostes (Haroldostes) rugiceps (Germar)

New record. ARGENTINA: Misiones: Pozo Azul, (Eldorado), 15-25.I.1999, leg. Rehinard Förster, one ex. (A. Ballerio collection); Argentina, Misiones: Puerto Iguazu, X.1997, leg. Rehinard Förster, one ex. (Instituto Argentino de Investigaciones de Zonas Aridas collection, Mendoza, Argentina).

Remarks.Germarostes (Haroldostes) rugiceps is a widespread common species which according to Paulian (1982) occurs in Brazil (i.e. Bahia, Goiás, Minas Gerais, Paraná, Espírito Santo, São Paulo), in Paraguay and in Panama (very doubtful record). Identification of Argentine material was made by comparison with the type at the Muséum National d'Histoire Naturelle (Paris, France).

Germarostes (Haroldostes) diffundus (Petrovitz) (Figs 1, 2)

New record. ARGENTINA: NE Argentina, Corrientes: Laguna Ibera, Colonia Pellegrini, 6-14.II.1999, G M Carpaneto leg., 60 exx.; ibidem, 1-12.XI.1999, G M Carpaneto, L Facchinelli & L. Valerio leg.; Reserva Natural del Iberá, reserve station, light traps in forest, h 21:00-24:00, 5 exx.; ibidem, light traps in forest clearings, h 20:00-24:00, 2 exx; light traps in rural areas, h. 20:00-24:00, 70 exx.; ibidem, 25-31.X.1999, G M Carpaneto, L Facchinelli & L Valerio leg., light traps in rural areas, h 20:00-24:00, 70 exx. (A Ballerio, G Carpaneto and Instituto Argentino de Investigaciones de Zonas Aridas collections).

Remarks. Morphology. All of the specimens collected from Corrientes belong to the same species and are here attributed to G diffundus. However, the type series of this species shows a geographical variation difficult to interpret from a taxonomic point of view. The holotype (collected on the western slopes of the Andes of Ecuador: Santo Domingo and preserved in the Institut Royal des Sciences Naturelles de Belgique, Brussels, Belgium) shows some remarkable differences if compared with the paratypes (all collected East of the Andes in Ecuador and in Brazil: Amazonas, São Paulo and Minas Gerais, preserved in the Muséum d'Histoire Naturelle de Genève, Switzerland). Most differences are found on the elytral pattern of striae: the 2^nd and 3^rd striae join together only near apex, and the 7^th stria joins and fuses with the 4^th. All the paratypes but one match the Argentine specimens quite well in both general habitus and elytral pattern (2^nd and 3^rd striae joining together at the beginning of apical declivity, and 7^th stria ending without joining any other stria). One paratype from Buritis (Minas Gerais) has a completely different elytral pattern (2^nd, 3^rd, 4^th, 5^th and 6^th striae joining together), a metallic green colour of elytra and some minor differences in punctuation, probably belonging to a different species. Other variation in the specimens examined, especially among the over 200 individuals collected in Argentina, lies in the punctures of pronotum, in the development of the smooth area at the apical third of the outer face of metatibia, and in the development of the metatibial apical callosity. Without additional specimens from the whole distribution range of this "species", we cannot provide any interpretation of such variability. Germarostes (Haroldostes) diffundus is also reported from Paraguay (Paulian 1982), and these specimens are very similar to the Argentine material. Petrovitz (1976) lists also paratype(s?) from Bolivia, but we were unable to locate any of them in Geneva or Brussels Museums.

Study area and ecological notes. All of the specimens from Argentina were collected near and within the Ibera Natural Reserve (Ramsar site no. 1162: Lagunas y Esteros del Iberá, designation date: 18.01.2002). This is an important protected area (28°31'S 057°09'W), including 24,550 ha of lakes, swamps, marshes and sandy banks, at 65 m above sea level. Owing to the extension of rice cultivations and grazing lands for cattle, the arboreal vegetation is reduced to some thickets and very small semideciduous woodlands up to 5-8 m tall, mainly composed of Croton urucurana, Ocotea acutifolia and Sapium haemastospermum. These are the last remnants of a riparian forest belt surrounding the lake, which now can be observed only near the research station and the wardens' house.

The study area is situated in the transition zone between Chaco and Pampas, the so-called Mesopotamic zone (Soriano et al 1992, Anonymous 2002). In particular, it deals with a vast mosaic of marshes, swamps, grasslands and subtropical forests growing around the lakeshore. The average annual temperature for the region is 21ºC, while the average monthly temperature ranges from 16ºC in June/July (winter) to 27ºC in January/February (summer). The maximum high temperature recorded is 44ºC, while the minimum low is -2ºC. The relative humidity is high, with minima in the summer of about 60% and maxima in the winter above 75%. Rainfall ranges between 1,200 and 1,500 mm annually. There is no clear hydrological seasonality; however, the trends are hot and rainy summers alternated to cold and dry winters. Strong rains also occur primarily in spring and autumn.

The collecting circumstances of G. diffundus in the study area are worth of notice: all the specimens were collected at light (which is fairly common for many species of Ceratocanthinae), and the majority of them (over 200) were found in bare rural areas within the rural settlement of Colonia Pellegrini (about 500 inhabitants), where trees are very scarce, apart from few Eucalyptus and some local species utilized for fuelwood or local timber-work. The nearest woodland around the research station is situated at 5 km from the settlement, on the opposite shore of the main water basin (the Ibera Lake). This is unusual for the Ceratocanthinae, which are mostly found in forests or woodlands. Unless one argues that they are highly vagile and can disperse over large barriers, they probably should live somewhere in this bareland, maybe in subterranean termite nests and/or in subterranean rotting wood. It must be stressed that a search for them under the bark of dead trees, in rotten woods, leaf litter, termite mounds, carrion and fungi gave negative results.

Only few specimens were collected near the forest at the reserve station, but this shortage of collected individuals could be due to the fact that electric power was not available there, and nocturnal sampling were conducted for a short time with a portable battery light. Moreover, this shortage could also be due to the greater ease in finding these small beetles on paved surfaces rather than on forest and grassy soil, during nocturnal sampling. Interestingly, the aforesaid collecting circumstances are about the same collecting circumstances of G. diffundus in the Cerrado near São Paulo (Brazil) (F Z Vaz-de-Mello, pers. comm.).

Acknowledgments

We thank G Cuccodoro (MHNG) and P Grootaert (IRSNB) for allowing us to examine the type material of G. diffundus, preserved in the collections of their museums; Albert Allen (Boise, Idaho, USA) for providing specimens of G. rugiceps and to Fernando Z Vaz-de-Mello (Xalapa, Mexico) and Federico C Ocampo (Lincoln, Nebraska, USA) for advice. We are also grateful to Claudio Rossi and Steven Loiselle who coordinated the ecological research of the EC project "The Sustainable Management of Wetland Resources in MERCOSUR", and financed the zoological surveys to Ibera Lake. Special thanks to Mario Toledo (Torrile, Parma, Italy) for executing the habitus drawing.

Received 01/III/07. Accepted 21/VII/08.

Edited by Celso Oliveira Azevedo - UFES

• Anonymous (2002) Information sheet on Ramsar Wetlands (RIS) — Argentina, Lagunas and Esteros del Iberá, 2002 (The Ramsar Convention on Wetlands) http://www.ramsar.org/ris/ris_argentina_ibera_e.htm [Accessed in 2 November 2005]
• Howden H F, Gill B D (2000) Tribes of New World Ceratocanthinae, with keys to genera and descriptions of new species (Coleoptera: Scarabaeoidea). Sociobiology 35: 281-329.
• Ocampo F C, Ballerio A (2006) Phylogenetic analysis of the scarab family Hybosoridae and monographic revision of the New World subfamily Anaidinae (Coleoptera: Scarabaeoidea). 4. Catalog of the subfamilies Anaidinae, Ceratocanthinae, Hybosorinae, Liparochrinae, and Pachyplectrinae (Scarabaeoidea: Hybosoridae). Bull.Univ. Nebraska State Mus 19: 178-209.
• Ohaus F (1910) Neue Coleoptera Lamellicornia aus Argentinien (Col.). Deutsche Entom Z 1910:173-186.
• Ohaus F (1911) Neue Coleoptera Lamellicornia aus Argentinien (Col.). Deutsche Entom Z 1911: 553-565.
• Paulian R (1982) Révision des Cératocanthides (Coleoptera Scarabaeoidea) d'Amérique du Sud. Mém Mus Nat d'Hist Natur, ser A, Zoologie 124: 1-110+XVIII pl.
• Petrovitz R (1976) Acanthocerinae und Aphodiinae aus Ecuador und von den Galapagos-Inseln (Coleoptera Scarabaeidae). Mission zoologique belge aux îles Galapagos et en Ecuador (N et J Leleup, 1964-1965) 3: 275-292.
• Soriano A, León R J C, Sala O E, Lavado R S, Deregibus V A, Cahuepe M A, Scaglia O A, Velázquez C A, Lemcoff J H (1992) Río de la Plata grasslands, p.367-407. In Coupland R T (ed) Natural grasslands, Ecosystems of the World, v 8. Elsevier, Amsterdam, xiv+470p.

Publication Dates

• Publication in this collection
  27 Mar 2009
• Date of issue
  Feb 2009

History

• Accepted
  21 July 2008
• Received
  01 Mar 2007