Abundance of stable flies on heifers treated for control of horn flies with organophosphate impregnated ear tags

Abstract

Ear tags containing 40% organophosphate insecticides (diazinon or diazinon plus chlorpyrifos-ethyl) were applied to control Haematobia irritans (L.) (Diptera: Muscidae) in treated (TG01 and TG02) and untreated (UG01 and UG02) groups of Holstein heifers born in 2001 and 2002, respectively. Control and treated groups were assessed for the abundance of Stomoxys calcitrans (L.) (Diptera: Muscidae) from August 2001 to April 2002 and again from August 2002 to April 2003. The treatment had a high efficacy for control of horn flies (maximum median number per heifer of TG01 and TG02 = 5) but a low effect on the abundance of stable flies. The total numbers of S. calcitrans were 1251 (42.9% of the total) and 1668 (57.1%) for TG01 and UG01, and 1423 (48.8%) and 1494 (51.2%) in TG02 and UG02, respectively. No significant difference in stable fly burden was found in 55 of the 76 weeks evaluated. A unimodal peak of abundance in the spring was found during the first fly season, and a bimodal abundance, with peaks in the spring and autumn, during the second season. No strong associations between horn fly and stable fly burdens was found in individuals of the CG01 (correlation coefficient = 0.13, P > 0.05) or CG02 (correlation coefficient = 0.538, P < 0.05, determination coefficient = 0.289).

First survey of seasonal abundance and daily activity ofStomoxysspp. (Diptera: Muscidae) in Kamphaengsaen Campus, Nakornpathom province, Thailand

“…Globally, the most important captures were made during the warm and rainy season for all the species in both farms but these values were relatively low in comparison with others studies (Gilles, 2005;Lysyk, 1993;Guo et al, 1998;Heath, 2002;Guglielmone et al, 2004). It appears difficult to explain these low values by the climatic parameters.…”

Surtos por Stomoxys calcitrans em gado de corte no Mato Grosso do Sul

“…Os (Guglielmone et al 2004). Desta forma, pelo menos em princípio, a primavera se apresenta como o período de pico populacional desta espécie também no Mato Grosso do Sul, o que, somado a outros fatores predisponentes (tais como qualidade, quantidade e extensão dos sítios de reprodução), pode representar um risco potencial de surtos no Estado.…”

“…Embora o controle químico seja, em geral, a opção primariamente adotada por produtores, este método não é considerado sustentável no caso deste parasita, sendo indicado apenas em situações emergenciais. O uso, tanto de brincos OF, quanto de inseticidas pour-on, foi considerado de "pouca ou nenhuma eficácia" por produtores locais, coincidindo com estudos prévios (Guglielmone et al 2004). Estas formulações resultam em maiores concentrações do inseticida nas regiões mais próximas aos locais de aplicação, ou seja, áreas dorsais e laterais superiores do animal (Taylor et al 1985, Hamel & Van Amelsfoort 1986, Mwangala et al 1993, as quais não coincidem com os locais preferenciais de distribuição de S. calcitrans nos bovinos, notadamente membros torácicos e pélvicos (Bittencourt & Moya Borja 2002).…”

Stomoxys calcitrans (Diptera: Muscidae) outbreaks: current situation and future outlook with emphasis on Brazil

“…Regardless of the insecticide formulation or class, the low efficacy of insecticide treatments for controlling adult S. calcitrans has been empirically observed by producers and confirmed in field studies (CAMPBELL & HERMANUSSEN, 1971;GUGLIELMONE et al, 2004). Thus, control measures should primarily target immature stable flies and their sites of development, improving the overall effectiveness of stable fly control strategies.…”