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Updated: Nov 2, 2025
Preparation of Virus-Enriched Inoculum for Oral Infection of Honey Bees Apis mellifera
Published on: August 26, 2020
Adapted tolerance to virus infections in four geographically distinct Varroa destructor-resistant honeybee
Barbara Locke1, Srinivas Thaduri2, Jörg G Stephan2
1Department of Ecology, Swedish Species Information Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden. barbara.locke@slu.se.
Abstract:
The ectoparasitic mite, Varroa destructor, is unarguably the leading cause of honeybee (Apis mellifera) mortality worldwide through its role as a vector for lethal viruses, in particular, strains of the Deformed wing virus (DWV) and Acute bee paralysis virus (ABPV) complexes. Several honeybee populations across Europe have well-documented adaptations of mite-resistant traits but little is known about host adaptations towards the virus infections vectored by the mite. The aim of this study was to assess and compare the possible contribution of adapted virus tolerance and/or resistance to the enhanced survival of four well-documented mite-resistant honeybee populations from Norway, Sweden, The Netherlands and France, in relation to unselected mite-susceptible honeybees. Caged adult bees and laboratory reared larvae, from colonies of these four populations, were inoculated with DWV and ABPV in a series of feeding infection experiments, while control groups received virus-free food. Virus infections were monitored using RT-qPCR assays in individuals sampled over a time course. In both adults and larvae the DWV and ABPV infection dynamics were nearly identical in all groups, but all mite-resistant honeybee populations had significantly higher survival rates compared to the mite-susceptible honeybees. These results suggest that adapted virus tolerance is an important component of survival mechanisms.
Insights
Honeybee populations resistant to Varroa mites show enhanced survival against viruses like Deformed wing virus (DWV) and Acute bee paralysis virus (ABPV). This suggests virus tolerance, not just mite resistance, is key to honeybee survival.
Area of Science:
- Apiculture
- Insect pathology
- Genetics
Background:
- Varroa destructor mites are a primary threat to honeybees (Apis mellifera), transmitting lethal viruses.
- While mite resistance in honeybees is documented, host adaptation to vectored viruses is less understood.
- Understanding virus tolerance is crucial for honeybee health and colony survival.
Purpose of the Study:
- To compare virus tolerance and resistance in mite-resistant honeybee populations.
- To assess the contribution of virus tolerance to the survival of mite-resistant honeybees.
- To evaluate survival rates of mite-resistant vs. mite-susceptible honeybees infected with DWV and ABPV.
Main Methods:
- Inoculation of caged adult bees and larvae from four mite-resistant European honeybee populations and one susceptible population with Deformed wing virus (DWV) and Acute bee paralysis virus (ABPV).
- Monitoring of virus infection dynamics using RT-qPCR over a time course.
- Comparison of survival rates between mite-resistant and mite-susceptible honeybee groups.
Main Results:
- Virus infection dynamics (DWV and ABPV) were similar across all tested honeybee populations (adults and larvae).
- Mite-resistant honeybee populations exhibited significantly higher survival rates compared to mite-susceptible populations.
- No significant difference in virus infection levels was observed, indicating tolerance rather than resistance.
Conclusions:
- Honeybee populations adapted to Varroa mites demonstrate enhanced survival against vectored viruses.
- Virus tolerance plays a significant role in the survival mechanisms of mite-resistant honeybees.
- Further research into the genetic basis of virus tolerance could inform breeding programs for Varroa mite resistance.
