Restructuring of the honey bee chain and varroa resistance breeding and selection programme : the EurBeST study explores possibilities for in-creasing the varroa resistance of commercially available honey bees by selective breeding and analyses ways to improve beekeepers’ access to resistant material.
Date: 2022-03-15
Institutions: Directorate-General for Agriculture and Rural Development
Subjects: EU agricultural market, animal breeding, apiculture, biodiversity, biology, biotope, ecosystem, environmental research, genetics, marketing, pest

Conclusions and recommendations based on the EurBeST findings: 

The results of the EurBeST study contribute to achieving the goals of the  
EU Green Deal, specifically of the Farm to Fork and Biodiversity strategies. 

PROJECT TEAM 

RESTRUCTURING OF THE HONEY BEE CHAIN 
AND VARROA RESISTANCE  
BREEDING & SELECTION PROGRAMME 

A pilot study comparing varroa resistant bees 
under commercial beekeeping conditions  

AGRI-2017-0346  

www.eurbest.eu 

www.llh.hessen.de                     

www.inrae.fr 

www.crea.gov.it 

www.consultech.de 

Copyright of pictures: LLH, INRAE, CREA, M. Kovačić <Marin.Kovacic@fazos.hr> 

Directorate-General for Agriculture and 
Rural Development (DG AGRI) 

RESTRUCTURING OF THE HONEY BEE CHAIN AND  
VARROA RESISTANCE BREEDING & SELECTION PROGRAMME 

ISBN 978-92-76-28923-4  

 KF-02-21-042-EN-N    
DOI:10.2762/066488 

 
 
 
The EurBeST study explores possibilities for in-
creasing the varroa resistance of commercially 
available honey bees by selective breeding and 
analyses ways to improve beekeepers’ access to 
resistant material. 

     Beekeeping: a small sector of huge importance! 

The apicultural sector in Europe represents a limited market 
compared to other agricultural sectors, but the pollination  
services provided by beekeepers and their honey bees are  
essential to maintain healthy ecosystems and food production 
chains.  

      Honey bees are in trouble! 
Honey bees have been under huge stress for several years, 
due to intensification of agricultural practices as well as climatic 
changes and globalisation, which bring new diseases to bees. 
Amongst them is the parasitic mite Varroa destructor, which 
leads to the death of most infested colonies within a few  
months if no treatment is 
performed by beekeepers.  

     The varroa mite:  
a deadly menace for 
European honey bees 
This mite feeds on 
the adult bees and bee pu-
pae and, during this process, can transmit viruses. Since its 
arrival in Europe in the late 70’s, varroa infests most colonies 
and represents the most impacting pathogen threat for honey 
bees and the beekeeping industry worldwide. 

     Varroa-resistant bees, a sustainable prospect for beekeepers! 
Beekeepers only have limited solutions to control the mite. A new promising 
and sustainable solution emerges: some honey bee populations are able to 
survive mite infestation, in the absence of treatments. These survivor bees 
develop defences to maintain the parasite population under control. As this 
ability can be transmitted to the next generation, it opens up the possibility 
for beekeepers to specifically select and breed for varroa-resistant bees. 

The largest study on honey bee selection ever 
conducted in Europe, to answer the following 
questions:  

  What is the status and entity of the honey bee breeding and  

reproduction market in the EU? 

  What is known about varroa resistance? Do varroa-resistant bees  

exist in the EU? Are they available for beekeepers to use? 

  Are beekeepers interested in using varroa-resistant honey bees?  

What do they expect when they buy honey bee queens? 

  What methods are available for selecting varroa-resistant bees? 

Do they work? 

  What are the efforts and costs to obtain varroa-resistant honey bee stock? 

EurBeST team and study design 

  Coordinating body with experts in beekeeping, bee biology, breeding,  

economics and statistics 

  Analysis of the EU market for honey bee reproductive material 

  Literature review and expert interviews on the state of play in varroa resistance 
  Queen customer survey on expectations and quality 

  5 large-scale case studies (CS) in 7 EU countries comparing varroa-resistant  

lines under commercial beekeeping conditions 

  130 participating beekeepers 

  23 EurBeST selected lines belonging to 6 subspecies / races  

  > 3 500 colonies tested for one full beekeeping season 

  More than 40 000 single records collected 

EU market for honey  
bee reproductive 
material 

Despite a high demand, availability of varroa-resistant stock is limited 
Despite a high demand, availability of varroa

Beekeepers’ views on the 
queen market: high expecta-
tions, but moderate satisfaction 
 Most important for beekeepers 
is to have disease-resistant  
colonies, followed by a good 
productivity.  

 Beekeepers are least satisfied 
with the disease resistance of 
available stock. 

Local adaptation is important 
Strong interactions between genetic and environmental factors re-
gulate honey bee colony general performance as well as varroa-
resistance potential. Practically, the same line of bees used in two 
different locations may perform very differently, highlighting the 
need for local selection strategies.  

Higher resistance of selected stock  

 While starting with a trend of higher infestation in 

autumn 2019, the EurBeST lines were on average 
less infested compared to commercial bee-
keepers' own stock by the end of test season in 
summer 2020. 

 After a full season without any treatment against  
varroa, the infestation of several lines clearly  
remained below the 3% infestation threshold for  
required mite treatment, showing promising  
avenues for a treatment-free beekeeping. 

 Varroa infestation levels closely correlate with the 
bee colonies' hygiene behaviour. Different expres-
sion of hygiene behaviour among the EurBeST 
lines thus serves as a useful selection criterion for 
mite resistance. 

Economic Aspects 

Selection is expensive...  
Testing a colony costs 193 € on average, ranging from  
273 € in Germany to 85 € in Greece. 

… especially selection for varroa resistance!  
The main costs of colony evaluation derive from assessing varroa 
resistance traits. Varroa infestation monitoring and hygienic behavi-
our testing together reach almost 20%, while more than 60% of the 
total results from assessing specific traits of bee defense against 
varroa.  

Selection works! 

The EurBeST selected lines show similar survival rates to the 
beekeepers` stocks. While there is not much difference on average 
for the general traits, the EurBeST lines clearly outperform the  
commercial beekeepers` own stock with regard to mite resistance.  
Some of the selected lines demonstrated high productivity  
combined with low varroa infestation. 

Queen prices often do not cover these costs! 
The average costs for queen production across 
the study countries amount to 22.58 € per queen, 
with the main share of costs originating from  
labour, which significantly varies between  
countries. The average selling price per queen 
was 23.32 €.