Diversity and seasonality of horse flies (Diptera: Tabanidae) in Uruguay.

Horse flies (Diptera: Tabanidae) cause direct and indirect losses in livestock production and are important vectors of pathogens. The aim of this study was to determine the diversity and seasonality of horse fly species at an experimental farm in Tacuarembó and the diversity of species in different departments of Uruguay. For 20 months, systematic collections were performed in two different environments at the experimental farm using Nzi and Malaise traps.

Influence of selective treatment of bulls on the infestation of Haematobia irritans on untreated cows.

The distribution of Hematobia irritans is not homogeneous in cattle populations. Generally, between 15% and 30% of bovines carry more than 50% of the flies, and higher infestations occur in bulls. In this study, the effect of treating the bulls with ear tags containing 40% diazinon on the infestation of flies on the herd during the breeding season was evaluated.

Insecticide susceptibility of horn flies, Haematobia irritans (Diptera: Muscidae), in the State of Mato Grosso do Sul, Brazil.

Horn fly susceptibility to insecticides was evaluated in the state of Mato Grosso do Sul, Brazil, from October 2000 to September 2002. Insecticide bioassays (n=57) were conducted in 38 ranches from 14 municipalities throughout the state. Horn flies from wild populations were collected on cattle and exposed to filter papers impregnated with cypermethrin, permethrin, or diazinon and mortality was assessed after two hours.

[Susceptibility of the horn fly (Haematobia irritans) to insecticides in the Tabuleiros Costeiros region in states of Alagoas, Bahia and Sergipe, Brazil].

Susceptibility of horn fly populations to insecticides was evaluated at the Tabuleiros Costeiros region in the states of Alagoas, Bahia, and Sergipe from April 2001 to December 2002. A total of 37 bioassays were conducted in 23 ranches from 12 municipalities. Fly susceptibility was determined by the impregnated filter paper method using the active ingredients diazinon, permethrin, and cypermethrin.

Evaluation of 65% permethrin spot-on for prevention of canine visceral leishmaniasis: effect on disease prevalence and the vectors (Diptera: Psychodidae) in a hyperendemic area.

A study was designed to examine the effect of 65% permethrin spot-on on the prevalence of canine visceral leishmaniasis and the abundance of sand flies in two neighborhoods in Corumbá, Mato Grosso do Sul, Brazil known to have a high prevalence of visceral leishmaniasis. An enrollment survey was conducted to determine the prevalence of visceral leishmaniasis. Area residents were provided with information about the project; the study area was defined, and all dogs (160 in Cristo Redentor and 230 in Popular Velha) identified in the study area were enrolled.

Susceptibility to diazinon in populations of the horn fly, Haematobia irritans (Diptera: Muscidae), in Central Brazil.

From October 2000 to April 2001, insecticide bioassays were conducted in 18 ranches from 10 counties in the states of Mato Grosso and Mato Grosso do Sul, in Central Brazil. Horn flies from wild populations were exposed to diazinon-impregnated filter papers immediately after collection on cattle, and mortality was recorded after 2 h. A high susceptibility to diazinon was observed in all tested populations.