Resistance phenomena to amitraz from populations of the ectoparasitic mite Varroa destructor of Argentina

M.MAGGI,; RUFFINENGO S.; NEGRI P; EGUARAS, M

PARASITOLOGY RESEARCH

SPRINGER

Año: 2010 p. 1 - 2

0932-0113

Abstract In Argentina, Varroa destructor resistance to coumaphos has been previously reported. However, the status of mite susceptibility to other hard acaricides is still unknown. At present, high infestation levels of V.  destructor are being detected in colonies of Apis mellifera  V. destructor are being detected in colonies of Apis mellifera are being detected in colonies of Apis mellifera after treatment with amitraz. The aim of the present studywas to determine the LC50 of amitraz in V. destructor from three apiaries with high mite density after treatment withthe acaricide. The LC50 values were 3.9, 3.5, and 3.7 ìg/ Petri dish for mites from three different apiaries. Significant LC50 differences were detected between resistant and susceptible mites. LC50 increased 35–39-fold when compared to the corresponding baseline, suggesting the development of resistance. These results are the first report of resistance to amitraz in V. destructor in Argentina and extend the knowledge according to the status of acaricides resistance in the country.