Varroa destructor: when reversion to coumaphos resistance does not happen

The ectoparasitic mite Varroa destructor is potentially the greatest threat to honey bee colonies of Apis mellifera worldwide. Acaricide rotation is widely accepted to mitigate development of resistance to synthetic acaricides. When a population has developed resistance to a compound, cessation of its use can result in some degree of susceptibility. This study aimed to follow changes in the susceptibility of mites to coumaphos in a population not treated with the acaricide over many generations. The LC50 increase over the years from 2 to 8-fold. Considering that coumaphos had not been used for nine years in the studied apiary, the results provided here lead to reflections about the problem of the resistance phenomenon and its populations dynamics.Varroa destructor: cuando la reversion de la Resistencia a cumafos no ocurreEl acaro ectoparasito Varroa destructor constituye una de las mayores amenazas en el mundo para las colmenas de Apis mellifera. La rotacion de acaricidas es una medida ampliamente aceptad...