Evaluation of tagetes minuta L. essential oils to control varroa destructor (acari: varroidae).

CHAMORRO, ESTER; SEQUEIRA, ALFREDO F.; VELASCO, GUSTAVO A.; ZALAZAR, MARIA FERNANDA; BALLERINI, GRISELDA

Journal of the Argentine Chemical Society

ASOCIACIÓN QUÍMICA ARGENTINA

Lugar: Buenos Aires; Año: 2011 vol. 98 p. 39 - 47

0365-0375

The Varroa destructor, an ectoparasitary mite of the Apis mellífera, causes serious damage to beekeeping. Synthetic acaricides have been used to combat the V. destructor but mites have developed resistance against them, moreover, it has been reported that synthetic acaricides contaminate honey and wax. Natural products, such as essential oils, might be an option to control V. destructor. Acaricidal effects of Tagetes minuta L. essential oils on V. destructor mites were studied. The essential oils were extracted by steam distillation from different parts of the plant in diverse stages of their vital cycle. Live V. destructor mites were sampled from an infested experimental apiary to which no previous acaricide treatments had been applied. Groups of ten mites were kept in Petri dishes with small oiled wooden sticks under controlled atmosphere. After three hours of exposure, the essential oil obtained from flowers showed the highest toxicity for the mites, causing 85 % of mortality, while mortality counts corresponding to the oil from leaves of bloomed plants and oil from leaves of plants that had not yet bloomed were 57 % and 38 % respectively. After six hours, most mites exposed to any of the oils were dead. Oils toxicity for bees was also evaluated. Groups of ten bees each were enclosed with wooden sticks that had been treated with the essential oil extracted from flowers and no toxic effect was found after three and six hours of exposure. These results opens the possibility of developing new alternative methods to control V. destructor.