Short communication. Comparison of the efficacy of Apiguard (thymol) and Apivar (amitraz) in the control of Varroa destructor (Acari: Varroidae)

Abstract

The present study compared the efficacy of Apivar (a.i. amitraz) and Apiguard (a.i. thymol) in controlling the mite Varroa destructor during spring 2010 and autumn 2011, in the Balearic Islands (Spain). Number of fallen mites (NFM) was counted weekly and the efficacy of treatments was evaluated by using the percentage of reduction of the average daily fallen mites (%R). During spring assay, the average NFM was highly reduced in Apiguard (89.8%) compared to Apivar (64.3%) group, with significant differences between Apiguard and control group (untreated group) in post-treatment week. In autumn assay, Apivar and Apiguard colonies had an average reduction of the NFM of 17.9% and 30.8% respectively, showing a tendency in reduction between control and Apiguard group in post-treatment week. In both assays, %R was higher in Apiguard than in Apivar, but no significant differences were found between treatments in any of the seasons. Apiguard was less efficacious during November-December, probably due to the low external temperatures that hampered an optimal volatilization of the product. The lower efficacy of Apivar is probably related to the resistance of V. destructor to this chemical miticide, which has been used during the last 30 years. Results of this study showed that in Mediterranean conditions, spring is an appropriate period for applying Apiguard to the colonies, whereas application in late autumn would decrease the efficacy of the product. Apiguard may represent an alternative product for integrated control due to the low risk of mite resistance and residues in bee products.Additional key words: honeybee; Apis mellifera; mite control; treatment effectiveness; essential oil; falling mites.

Patterns in Varroa destructor depend on bee host abundance, availability of natural resources, and climate in Mediterranean apiaries

“…Our finding that in this period organic treatments were more effective than synthetic treatments in reducing Varroa abundance is consistent with another study conducted in Balearic islands (Leza et al, 2015) that obtained a higher efficacy for Apiguard (organic treatment) compared to Apivar (synthetic treatment), both in spring (April to May) and in late autumn (November to December). The most significant impact of treatment was found in the second period of the year, the season in which population sizes of Varroa tend to be lower.…”

“…The most significant impact of treatment was found in the second period of the year, the season in which population sizes of Varroa tend to be lower. Our finding that in this period organic treatments were more effective than synthetic treatments in reducing Varroa abundance is consistent with another study conducted in Balearic islands (Leza et al, 2015) that obtained a higher efficacy for Apiguard (organic treatment) compared to Apivar (synthetic treatment), both in spring (April to May) and in late autumn (November to December). Moreover, Loucif-ayad et al (2010) found similar results in a comparative field study of treatments carried out in Algeria, Western Mediterranean, during autumn.…”

“…Moreover, Loucif-ayad et al (2010) found similar results in a comparative field study of treatments carried out in Algeria, Western Mediterranean, during autumn. A previous study (Leza et al, 2015) found spring to be the most appropriate period for applying the anti-varroa treatment, resulting in reduced abundance of Varroa. Thymol, an organic treatment, could represent an alternative to integrated control strategies against V. destructor, having a low risk of residues and resistance (Rosenkranz et al, 2010).…”

“…Thymol, an organic treatment, could represent an alternative to integrated control strategies against V. destructor, having a low risk of residues and resistance (Rosenkranz et al, 2010). A previous study (Leza et al, 2015) found spring to be the most appropriate period for applying the anti-varroa treatment, resulting in reduced abundance of Varroa. The inconsistency of treatment impacts on abundance in the present study could be as a result of the fact that more than 35% of the treatments were applied in a sub-optimal period, being too early (January-February) or too late (May-June), even if may be affected by an external temperature.…”

Türkiye’de Varroa destructor’a (Acari: Varroidae) karşı kullanılan sentetik akarisitlerin değerlendirilmesi: duman amitrazda direnç mi yoksa yanlış kullanım mı?

“…[16][17][18] We detected a drop in the efficacy of coumaphos liquid in the second autumn, probably due to the lower external temperatures or internal (in-hive) conditions like colony population. A similar observation has also been reported by Semkiw et al 17 and Leza et al 19 with the studies of amitraz plastic strip. Although the results of the assessments of amitraz strips in our experiment are high/not variable, some researchers have gained variable results as 83.8% on average (78.8 -87.3%) in Italy and maximum 60.1% efficacy in Portugal.…”