Impacto en la exposición crónica a los principales acaricidas utilizados para el control de la varroosis tanto en el parásito (Varroa destructor) como en su hosopedador (Apis mellifera)

Abstract

The parasitic mite Varroa destructor is considered one of the greatest threats to the the European honey bee (Apis mellifera) that has caused great losses in colonies, bee production and pollination since it spread from its original host, the Asian honey bee (Apis cerana), to the European honey bee. Apis mellifera is used commercially to produce honey and other products and for pollination. In addition to the damage caused by cuticular lesions and the ingestion of hemolymph and adipocytes, V. destructor also acts as a virus vector, causing a weakening of the hives that can cause their death.Beekeepers have systematically controlled populations of this mite by applying acaricide substances to their colonies for years. The inadequate and continuous administration of these compounds, often without veterinary control, has favored the selection of resistant populations of Varroa to the different acaricides aplied. The presence of V. destructor resistant populations particularly to pyrethroids is currently one of the main challenges in the control this mite, specially to tau-fluvalinate, an apolar substance that persistently accumulates in wax and stored pollen.In the present Thesis, it has been demonstrated that the accumulation of this pyrethroid in the wax and the stored pollen of the colonies was related to a selection pressure over time that confers a greater advantage to varroas that have a resistant genotype. Likewise, the results obtained suggest that the persistent presence of high concentrations of this type of acaricide inside the hives may also favour the selection of Varroa populations with new mutations in the genome, which could increase their resistance to this compound.