Warwick researchers find fungal protection for bees

Research Lead

Researchers at Warwick University are examining naturally occurring fungi that kill the varroa mite, one of the main causes of the decline of honey bee populations worldwide. They are also exploring the most appropriate ways to deliver the killer fungus throughout hives using techniques ranging from bee fungal foot baths to powder sprays.

Bees world wide are suffering serious declines, with the varroa mite, which feeds on the circulatory fluid of honey bee pupae and adult bees one of the main causes. The mites activate and transmit diseases which reduce the life expectancy of the bees and cause the colony to decline.

Varroa has had a major impact in all countries where it has become established. For example it caused the loss of 30 – 50 percent of honey bee colonies when it first arrived in the UK, and is now endemic. The loss of honey bees on this scale is affecting the pollination of commercial crops and wild plants. While varroa originated in Asia, it has extended its range world-wide.

At present, management of varroa depends on chemical pesticides, but the mites are developing resistance. Biological control technologies could offer an alternative to pesticides, but no natural insect or other enemies of varroa species have been identified on the varroa, or on their bee hosts.

Now researchers at Warwick’s plant research group, Warwick HRI, and the government research centre Rothamsted Research, have found some new natural enemies of varroa from other hosts.

Researcher Dave Chandler said, “We examined 50 different types of fungi that afflict other insects to see if they would kill varroa. We needed to find fungi that are effective killers of varroa, had a low impact on the bees, and worked in the warm and dry conditions typically found in bee hives. Of the original 50 fungi we are now focusing on four that best match those requirements.”

The team is now looking for additional funding to further examine the effectiveness of these four fungi, and to look at the best way of applying the chosen fungi.