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Mites (Acari: Laelapidae) associated with sigmodontinae rodents in Entre Ríos Province, Argentina

Abstract

The richness, diversity, abundance and prevalence of mite species associated with sigmodontine rodents of different species in Entre Ríos province, Argentina are studied. Five of the six species of mites were reported for the first time in the study area. The richness and diversity of mites was higher on Oligoryzomys flavescens and O. delticola than on Akodon azarae. Androlaelaps rotundus was dominant and exhibited higher values of mean abundance and prevalence on A. azarae, Mysolaelaps microspinosus on O. flavescens and Gigantolaelaps mattogrossensis on O. delticola.

mites; Laelapidae; sigmodontine; Argentina


SHORT COMMUNICATION

Mites (Acari: Laelapidae) Associated with Sigmodontinae Rodents in Entre Ríos Province, Argentina

Vol. 96(8): 1171-1172, November 2001

Agustín M Abba/+, Daniel E Udrizar Sauthier*, José B Bender*, Marcela Lareschi

Centro de Estudios Parasitológicos y de Vectores, Calle 2 Nº 584, 1900 La Plata, Argentina *Facultad de Ciencias Naturales y Museo, UNLP, La Plata, Argentina

The richness, diversity, abundance and prevalence of mite species associated with sigmodontine rodents of different species in Entre Ríos province, Argentina are studied. Five of the six species of mites were reported for the first time in the study area. The richness and diversity of mites was higher on Oligoryzomys flavescens and O. delticola than on Akodon azarae. Androlaelaps rotundus was dominant and exhibited higher values of mean abundance and prevalence on A. azarae, Mysolaelaps microspinosus on O. flavescens and Gigantolaelaps mattogrossensis on O. delticola.

Key words: mites - Laelapidae - sigmodontine - Argentina

Laelapidae is one of the most important families of the Acari Subclass in number of species (Strandtmann & Wharton 1958) and most of them are ectoparasites of vertebrates. In Argentina, most of the studies reported are on species associated with rodents in the province of Buenos Aires only. Relatively few ecological studies were made and the most relevant were obtained from the following localities: General Pueyrredon (Fernandez 1977), Punta Lara (Lareschi 1996) and Berisso (Liljesthröm & Lareschi 2001). Here, the richness, diversity, abundance and prevalence of mite species associated with sigmodontine rodents of different species were studied in Entre Ríos province, Argentina.

The mites were collected on rodents captured alive from 20 to 27 July of 1998. In total, 48 individuals were examined: Akodon azarae (27), Oli-goryzomys flavescens (11) and O. delticola (10). The specimens are housed at the Mammalogy Collection of the Department of Vertebrate Zoology, La Plata Museum, Argentina. The ectoparasites were recovered by hand from the host's coat. They were preserved in 70% ethanol and subsequently mounted on permanent slides for taxonomic identification. Representative specimens have been housed over to the Collection of the Department of Entomology, La Plata Museum. The identification of the mites is according to Furman (1972). For each host species the richness (S = number of species), Shannon diversity species index (H = -å [pi ln pi]), mean abundance (MA = total number of individuals of a particular parasite species - or taxonomic group - in a sample of a particular host species divided by the total number of hosts of that species, including both infected and non-infected hosts) and prevalence [P = (number of hosts infected with one or more individuals of a particular parasite species - or taxonomic group - divided by the number of hosts examined for that parasite species) x 100] were calculated.

The study area comprises the first 5 km of the Perucho Verna stream located in Villa Elisa (Entre Ríos, 32º10'S, 58º24'W). In total, 466 mites representing the following six species were collected from the 48 rodents: Order Parasitiformes, Family Laelapidae: Androlaelaps fahrenholzi (Berlese), Androlaelaps rotundus (Fonseca), Gigantolaelaps mattogrossensis (Fonseca), Laelaps manguinhosi Fonseca, Laelaps paulistanensis Fonseca, and Mysolaelaps microspinosus Fonseca. The number of mites collected and the values of mean abundance, prevalence, diversity index and richness on each rodent species are shown in Table I. The number of specimens of each mite species as well as the abundance, mean abundance and prevalence on every host species are shown in Table II.

Table I

Table II

Although the six species of mites have been previously recorded in Argentina (Lareschi & Mauri 1998), except L. manguinhosi (Lareschi et al. unpublished observation), the other five species are reported for the first time in the province of Entre Ríos. A. rotundus is specific on A. azarae. On the other hand, A. fahrenholzi and M. microspinosus are associated with all the host species. G. mattogrossensis, L. manguinhosi and L. pau-listanensis are specific at the host-genus level. Comparing mean abundance and prevalence, the sequence of hosts for M. microspinosus is O. flavescens, O. delticola and A. azarae.

Since many rodents are reservoirs of diseases, those species collected on different host species may play an important role in epizootics and in the perpetuation of diseases among them, as tularemia, relapsing fever and rickettsial infections (Tipton 1960). On the other hand, the dominance of each mite species on different host species, obtained in this study, are in line with similar studies carried out in localities of the province of Buenos Aires (Fernandez 1977, Lareschi 1996, Liljesthröm & Lareschi 2001). Acording to Kim (1985), who supports that in an ectoparasitic community the dominant species on a host species are usually well defined and consistent throughout with the range of its host distribution, these results are important because, allied with other sort of studies, constitute an important step for correct identification of the host.

To WO Udrizar Sauthier, R Imoberdoff and PM Simón for their valuable assistance in the field work, to PM Linardi (UFMG, Brasil) for his critical lecture of the manuscript, to IF de Cassé, Ernesto Lofeudo and SF Vizcaíno (FCNyM, Argentina) for the critical revision of the English and UFJ Pardiñas (FCNyM, Argentina) for the systematic revision of the rodents.

Table I | Table II

Supported partially by the municipality of Villa Elisa, Entre Ríos, Argentina.

+Corresponding author. E-mail: amabba@lycos.com and ferpao@netverk.com.ar

Received 8 March 2001

Accepted 31 July 2001

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  • Strandtmann RW, Wharton GW 1958. Manual of Mesostigmatid Mites, Contribution no. 4 of The Institute of The Acarology, CE Yunker, 330 pp.
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Publication Dates

  • Publication in this collection
    08 Jan 2002
  • Date of issue
    Nov 2001

History

  • Received
    08 Mar 2001
  • Accepted
    31 July 2001
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