Stomoxys calcitrans outbreaks in pastured beef cattle in the state of Mato Grosso do Sul, Brazil

Barros A. T. M., Koller W. W., Catto J.B. & Soares C.O. 2010. [Stomoxys calcitrans outbreaks in pastured beef cattle in the state of Mato Grosso do Sul, Brazil.] Surtos por Stomoxys calcitrans em gado de corte no Mato Grosso do Sul. Pesquisa Veterinaria Brasileira 30(11):945-952. Embrapa Pantanal, Rua 21 de Setembro 1880, Bairro Nossa Senhora de Fatima, Caixa Postal 109, Corumba, MS 79320-900, Brazil. E-mail: thadeu@cpap.embrapa.br The expansion of the alcohol industry has led to the installation of ethanol plants in areas traditionally occupied by beef cattle in the Brazilian Midwest. Stable fly (Stomoxys calcitrans) outbreaks associated with alcohol plants have been reported in Nelore cattle in Mato Grosso do Sul, Brazil, in the last two years. Visits to livestock ranches and alcohol plants were held in mid-November 2009 at the end of S. calcitrans outbreaks in the counties of Angelica and Ponta Pora, MS. Interviews, surveys and collections of immature stages of flies were conducted at the sites and the entomological material was taken to the laboratory for further emergency. High stable fly infestations and cattle bunching behavior were observed during visits. Stable fly breeding sites were found and emergence of adult flies occurred from material collected from both cattle ranches and alcohol plants. The set of information, on-site observation, and sampling results made possible a preliminary epidemiological approach on the dynamics of S. calcitrans outbreaks as well as a discussion of potential risk factors.