Antibody-Driven Defence: An Innovative Method for Safeguarding Honey Bees Against Varroa-Induced Viral Diseases

Summary

The ectoparasitic mite Varroa destructor threatens the health of honey bees, especially Apis mellifera. It can cause colony collapse through feeding or pathogen transmission if not properly managed. Various treatments have emerged, including hard and soft acaricides and biocontrol methods. However, a sustainable solution that reduces the mite-transmitted viral load without promoting mite resistance or harming honey bees has yet to be found. Thus, exploring alternative tools that target viral replication and host entry remains an overlooked opportunity.

V. destructor transmits several key viruses such as Kashmir bee virus (KBV), Sacbrood virus (SBV), Acute bee paralysis virus (ABPV), Israeli acute paralysis virus (IAPV), and Deformed wing virus (DWV), which significantly contribute to colony loss in western honey bees. While Australia currently remains DWV-free, it has high levels of IAPV and SBV, and when combined with Varroa parasitism, this could result in significant colony losses.

A recent study demonstrated that orally delivered anti-DWV IgY antibodies can act systemically to reduce DWV loads in naturally infected honey bees. These antibodies are generated in immunised hens, extracted from egg yolks, and delivered to bees via feeding, where they localise in the hemolymph and fat body of both adults and larvae. However, it remains uncertain whether IgY treatment alone is sufficient to improve overall colony health or if it must be integrated with existing Varroa control strategies, such as acaricides, for optimal effectiveness. Furthermore, the long-term effects of anti-viral IgY on developing bees require careful evaluation to ensure safety. Key challenges to widespread adoption include production costs and the current focus on single-pathogen targeting.

This project aims to develop an environmentally friendly, safe, and economically sustainable solution for managing honey bee viruses transmitted by V. destructor. By applying advanced protein engineering, we will design multivalent antigens to produce polyvalent IgY antibodies capable of simultaneously targeting multiple viral pathogens. This innovative approach will support the development of cost-effective, scalable, and practical antibody therapies, ultimately strengthening the resilience and productivity of Australia’s beekeeping and pollination industries.

Program

Honey Bee

Research Organisation

La Trobe University

Objective Summary

Create antibodies for bees against viruses by developing special proteins that trigger hens to produce protective antibodies in their eggs.

Collect and use these antibodies from egg yolks as a safe and sustainable treatment for honey bees.

Test if feeding these antibodies to bees can lower harmful viruses such as Deformed Wing Virus (DWV), Sacbrood Virus (SBV), and Israeli Acute Paralysis Virus (IAPV).

Check the long-term safety of the treatment to make sure it does not harm colony health, growth, or honey production.

Provide beekeepers with a new, environmentally friendly tool to reduce the impacts of Varroa mite–spread viruses and protect pollination services.