Susceptibility of Varroa destructor (Acari: Varroidae) to synthetic acaricides in Uruguay: Varroa mites' potential to develop acaricide resistance.
The purpose of this study was to estimate the acaricide susceptibility of Varroa destructor populations from Uruguay, which had never been exposed to synthetic acaricides. It was also to determine whether acaricide resistance to coumaphos occurred in apiaries in which acaricide rotation had been applied. Bioassays with acaricides against mite populations that had never been exposed to synthetic acaricides were performed, also against mite populations in which control failures with coumaphos had been reported. Additionally, coumaphos' effectiveness in honeybee colonies was experimentally tested. The lethal concentration that kills 50% of the exposed animals (LC(50)) for susceptible mite populations amounted to 0.15 μg/Petri dish for coumaphos and to less than 0.3 μg/Petri dish for the other acaricides. Coumaphos LC(50) was above 40 μg/Petri dish for resistant mites. The effectiveness of coumaphos in honeybee colonies parasitized by V. destructor ranged from 17.6% to 93.9%. LC(50) for mite populations susceptible to the most commonly applied miticides was determined, and the first case of coumaphos resistance recorded in Uruguay was established.
Maggi
Matías Daniel
MD
Arthropods Laboratory, School of Exact and Natural Sciences, Universidad Nacional de Mar del Plata, Funes, 3350, 7600, Mar del Plata, Buenos Aires, Argentina. biomaggi@gmail.com
Ruffinengo
Sergio Roberto
SR
Mendoza
Yamandú
Y
Ojeda
Pilar
P
Ramallo
Gustavo
G
Floris
Iganazio
I
Eguaras
Martín Javier
MJ
D056810:Acaricides / Q000494:pharmacology*; D000818:Animals; D001516:Bees / Q000469:parasitology; D003372:Coumaphos / Q000494:pharmacology; D004351:Drug Resistance; D016019:Survival Analysis; D014583:Uruguay; D057077:Varroidae / Q000187:drug effects*
D056810:Acaricides; D003372:Coumaphos