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Fungal control of Varroa jacobsoni (destructor) - HH0819SHB

The overall aims of this study are to:
(a) Extend investigations of the use of entomopathogenic fungi as microbial control agents of the varroa mite, Varroa destructor n. sp.;
(b) Quantify tritrophic interactions in a unique system of social insect - arachnid parasite - fungal pathogen.

Varroa destructor (previously termed Varroa jacobsoni) is a highly damaging ectoparasite of the European honey bee Apis mellifera. Pyrethroid resistance in varroa has been reported and there is an urgent need for alternative, sustainable forms of varroa management. Recent DEFRA-funded research identified entomopathogenic fungi as having potential for varroa control (HH0811SHB) and adult varroa mites were found to be highly susceptible to infection by entomopathogenic fungi in laboratory bioassays (HH0813SHB). The proposed study will examine the effect of a limited number of fungal isolates, selected in these previous studies, against varroa populations in honey bee colonies, underpinned by research on traits determining the activity of fungi as dose-dependent, nonpersistent biological control agents. It meets DEFRA’s aim of sustainable development, and matches policy objectives to conserve biodiversity and promote sustainable farming.

The research partnership between HRI and IACR-Rothamsted exploits established expertise in microbial control, mite, honey bee and pathogen dynamics and disease epidemiology. The intention is to produce a pre-commercial information resource that will be an important step towards implementing practical cost-effective and sustainable biocontrol of varroa.
1. Fungus optimisation. Determine the effects of abiotic factors on conidia survival and production.
2. Effect of fungus in varroa and bee populations. Quantify the activity against varroa mites of fungi applied to bees.
3. Environmental impact. Investigate the potential for fungal conidia to be disseminated to bee products and the environment.
4. Knowledge transfer. Engage stakeholders and exchange information.

The project will be done jointly by scientists from HRI and IACR Rothamsted who have an established collaboration in project HH0813SHB. HRI will lead objective 1, IACR Rothamsted will lead objective 2, objectives 3 & 4 will be done jointly. Research involving honeybee colonies will be done at IACR Rothamsted with technical support from HRI. The two institutes are sufficiently close for this to be practical and the system has worked well previously.

The project has been designed so that each Objective addresses a key aspect of the overall aims. Objectives 2 & 3 will depend upon the production of formulated conidia for experiments, which will be done as part of objective 1. The findings of the project will be integrated in objective 4. All objectives will exploit, build on and extend previously developed expertise in the collection and interpretation of biological information which will be applied to produce practical solutions of benefit to the bee industry and to DEFRA in the effective management of varroa.

This project has been designed around the seasonal availability of varroa mites and young bees (March to October). The production of sufficient quantities of varroa mites and honey bees at the right stage of development for experiments is technically challenging and subject to natural fluctuation. This can be accounted for in the design of individual experiments and practical experience gained during previous studies can be applied to ensure the achievement of these objectives. The proposal has been developed using Project Management procedures so that changes to the research schedule can be implemented in a structured way should unforeseen events occur.
Project Documents
• Final Report : Fungal control of Varroa jacobsoni (destructor)   (524k)
Time-Scale and Cost
From: 2002

To: 2006

Cost: £383,802
Contractor / Funded Organisations
Horticulture Research International, Warwick - HRI
Bee Health              
Biological Control              
Biotech-non GM              
Pest Control              
Sustainable Farming and Food              
Sustainable Production              
Varroosis (Varroa)              
Fields of Study