Honey bees (Apis mellifera) play a crucial role in the pollination of agricultural crops and the preservation of natural ecosystems. However, colony survival is increasingly threatened by various factors, including persistent infestation by Varroa destructor, a parasitic mite considered one of the main causes of colony losses.
To fight varroa, beekeepers implement integrated strategies, including chemical treatments based on acaricides. Among these, amitraz has long been one of the most widely used active substances, considered effective and with a low risk of resistance development. However, a recent study published by the National Reference Centre for Beekeeping at the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe) in the scientific journal Insects highlights that even the widespread use of amitraz is contributing to the selection of amitraz-resistant varroa populations.
Through a systematic review of the literature, 74 global studies on amitraz efficacy and resistance were analyzed. The findings show that only 31.7% of laboratory tests achieved an efficacy above 95%, considered the optimal threshold. Moreover, tests conducted in countries including France, the Czech Republic, the USA, and Argentina reveal a progressive increase in resistance levels.
The study stresses the urgent need for national monitoring programs and more conscious management strategies. In particular, it is essential to avoid improper use of acaricides, promote treatment rotation, and invest in research on new control methods.
Finally, the study highlights the lack of available data on other parasitic bee mites, such as Tropilaelaps spp. and Acarapis woodi, which may pose emerging threats in the near future. With this review, featured as a highlight on the cover of the journal Insects, the IZSVe reaffirms its role as a scientific reference point at the international level, particularly in bee health.
Read the scientific article in Insects »
