Varroa destructor control strategies in Apis mellifera colonies: A meta-analysis and systematic revision on natural compounds efficacy

Abstract

The parasitic mite Varroa destructor is a sanitary threat to beekeeping and causes significantlosses in honey bee colonies. Thus, different acaricides have been applied as a strategy tocontrol this disease. In the context of Integrated Pest Management, acaricides based onnatural compounds, such as organic acids and essentials oils, are chosen by beekeepers tominimize negative effects on colonies and hive products. Considering the variety of naturalactive ingredients reported to have varroacidal activity and their different application systems,the aim of this work was to synthesize and quantify scientific knowledge on the acaricideperformance of natural compounds to control V. destructor populations in Apis melliferacolonies. A systematic revision and a meta-analysis on the percentage of efficacy publishedfor these formulations were conducted by selecting articles published between 2002 and2022. According to our results, most publications investigated the efficacy of natural compoundsin temperate climates and in European honey bee colonies since Varroa control ispractically compulsory under these conditions. Thymol (THY) showed higher estimated efficacycompared to oxalic and formic acids (FA) and other essential oils (EOs). Variable efficacieswere found in colonies treated with the natural compounds considered in this studyaccording to different doses and application methods. The high between-study heterogeneityfound in this revision might be explained by several factors, including the number ofcolonies and intra-apiary variation. As such, standardized protocols for field assays are key toimproving efficacy evaluation. In addition, methodological implications are discussed.