The aim of this study was to determine resistance to the pesticides cypermethrin (pyrethroid) and... more The aim of this study was to determine resistance to the pesticides cypermethrin (pyrethroid) and diazinon (phosphate) in the horn fl y (Haematobia irritans) in the state of Tamaulipas, Mexico. A total of 36 farms were evaluated: 11 in the north, 14 in the central and 11 in the southern part of the state. For the cypermethrin diagnosis, impregnated fi lter papers with LD 50 and LD 99 were used, as well as glass vials impregnated with diazinon with LD 50 and LD 99 . Horn fl ies were collected from each farm, and exposed to 2.5, 6 and 0 µg/cm 2 of cypermethrin, and 0.01, 0.06 and 0 µg/cm 2 of diazinon. Three repetitions for each concentration were carried out. Mortality percentage was obtained after two hours of exposure to the insecticides. All ranches were resistant to cypermethrin in the northern part, while only two of them were resistant to diazinon. All ranches in the central part, except for one, showed resistance to cypermethrin, while in most of the farms the horn fl ies were susceptible to diazinon. Resistance to cypermethrin was found in all ranches in the southern part; however, eight of them (72%) were also resistant to diazinon. Therefore, we suggest that enhanced toxicity of diazinon (or negative cross-resistance), as observed in pyrethroid-resistant horn fl y fi eld population, could be used as a resistance management practice in the state of Tamaulipas.
Casi han desaparecido el acto de leer y la mirada reflexiva sobre el arte producido durante milen... more Casi han desaparecido el acto de leer y la mirada reflexiva sobre el arte producido durante milenios. Síntoma de este deterioro es la abrupta sustitución de la lógica filosófica por la del emprendedor en la reforma educativa
The aim of this study was to determine resistance to the pesticides cypermethrin (pyrethroid) and... more The aim of this study was to determine resistance to the pesticides cypermethrin (pyrethroid) and diazinon (phosphate) in the horn fl y (Haematobia irritans) in the state of Tamaulipas, Mexico. A total of 36 farms were evaluated: 11 in the north, 14 in the central and 11 in the southern part of the state. For the cypermethrin diagnosis, impregnated fi lter papers with LD 50 and LD 99 were used, as well as glass vials impregnated with diazinon with LD 50 and LD 99 . Horn fl ies were collected from each farm, and exposed to 2.5, 6 and 0 µg/cm 2 of cypermethrin, and 0.01, 0.06 and 0 µg/cm 2 of diazinon. Three repetitions for each concentration were carried out. Mortality percentage was obtained after two hours of exposure to the insecticides. All ranches were resistant to cypermethrin in the northern part, while only two of them were resistant to diazinon. All ranches in the central part, except for one, showed resistance to cypermethrin, while in most of the farms the horn fl ies were susceptible to diazinon. Resistance to cypermethrin was found in all ranches in the southern part; however, eight of them (72%) were also resistant to diazinon. Therefore, we suggest that enhanced toxicity of diazinon (or negative cross-resistance), as observed in pyrethroid-resistant horn fl y fi eld population, could be used as a resistance management practice in the state of Tamaulipas.
Casi han desaparecido el acto de leer y la mirada reflexiva sobre el arte producido durante milen... more Casi han desaparecido el acto de leer y la mirada reflexiva sobre el arte producido durante milenios. Síntoma de este deterioro es la abrupta sustitución de la lógica filosófica por la del emprendedor en la reforma educativa
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