Evaluation of Two Commonly Used Field Tests to Assess Varroa destructor Infestation on Honey Bee (Apis mellifera) Colonies

Marco Pietropaoli,Dariusz Gerula,Jernej Bubnič,Cecilia Costa,Jerzy Wilde,Patricia Aldea-Sánchez,Noureddine Adjlane,Giovanni Formato,Maja Ivana Smodiš Škerl,Ivana Tlak Gajger

doi:10.3390/app11104458

Abstract

Assessment of colony infestation by Varroa destructor is a crucial part of the Integrated Pest Management (IPM) applied to beekeeping. Natural mite fall, quantified by counting the mites on sticky sheets, is considered a reference method to estimate varroa infestation level in honey bee colonies. However, in recent years, alternative methods that can be used in field conditions have been investigated. In this paper, we report the results of the evaluation of two different methods to estimate the levels of varroa infestation. The experiment involved 151 honey bee colonies in nine apiaries of four countries (Algeria, Croatia, Italy, Poland). After the main honey flow, we compared the 10-day natural mite fall and the powdered sugar roll methods with the varroa population in each colony. According to our results, the powdered sugar roll method could be suggested to beekeepers as a suitable IPM tool for varroa control, while natural mite fall represents a more accurate method that could be adopted for selection/research purposes.

Highlights

Estimation of Varroa destructor mite infestation rate is an important tool for apicultural practices and studies
The highest correlation rates between the number of dispersal mites and infestation of samples tested using the powdered sugar roll method occurred in apiaries where colonies had more brood
The highest correlation rate was found in colonies with a lower amount of brood, statistically significant correlations were present in all conditions (Table 3)

Summary

Introduction

Estimation of Varroa destructor mite infestation rate is an important tool for apicultural practices and studies. It can be used to determine the appropriate timing for treatments, to assess the efficacy of the adopted varroa control strategies and, last but not least, to assess the genetic potential of a colony in terms of varroa resistance. Several methods for varroa mite infestation assessment have been described in detail by Dietemann [1]. A short review of methods adopted for the mite infestation level assessment is reported in Table 1. 4.0/)

Methods

Results

Discussion

Conclusion