TALLAHASSEE, Florida -- Research from Florida A&M University has found that fungal pathogens can effectively and economically control the small hive beetle (Aethina tumida) – an invasive pest of honeybees – while maintaining colony health. The results pave the way for more environmentally friendly biological controls in a pest management program.
Through a Southern Sustainable Agriculture Research & Education (SSARE) Graduate Student Grant, Saundra Wheeler studied the affects of entomopathogenic fungus Metarhizium anisopliae as a means of controlling the small hive beetle. She found that colonies treated with the fungus provided a various degree of control of small hive beetle populations during the course of the experiments compared to the control.
“The small hive beetle has played a major role in the substantial loss of honeybee colonies over the past several years,” said Wheeler.
Adults are long lived, surviving up to 181 days, and females may lay up to 2,000 eggs in their lifetime. Research has found that this pest can produce up to five generations per year. The larvae feed on honey, pollen and live brood, and tunnel and pierce wax combs.
“The rapid spread and high reproductive potential of the small hive beetle make it a serious threat of apiculture,” said Wheeler. “In addition, the small hive beetle is a vector of honeybee viruses, which makes it an even greater threat.”
Wheeler said that current research focuses on biological control options as an alternative to insecticides.
“Metarhizium anisopliae has been used to effectively control other beetle species, so this fungus could provide new avenues for an environmentally sound management of small hive beetle populations,” she said. “In addition, the fungus is harmless to honeybee colonies.”
In the SSARE project, “Efficacy of Entomopathogenic Fungi in Controlling the Small Hive Beetle: A destructive and invasive pest of honeybee colonies (GS11-100),” Wheeler treated small hive beetles in honeybee colonies with 10 g of Metarhizium 3020 and 2 g of Metarhizium 5680 fungal spores. She found that both provided a various degree of control of small hive beetle populations during the course of the experiments compared to the control. Colonies treated with Metarhizium 5680 spores exhibited significantly lower hive mortality rates.
“Both of the fungal spore treatments displayed a decrease in small hive beetle infestation levels greater than the control throughout the experiment, suggesting that both of the fungal spore treatments provided a various degree of control of small hive beetle populations during the course of the experiments,” said Wheeler. “The 2g of fungal spores of Metarhizium 5680 used in the experiment were the most efficacious in controlling populations while maintaining colony health throughout this field trial. The 10g of Metarhizium 3020 spores also reduced small hive beetle populations. However, colony health was not maintained.”
The limited results of the study, which was conducted over a three-month period, provide promising data on biological controls of pollinator pests, although timing, dose and frequency of applications of fungal pathogens requires further investigation.
Published by the Southern Region of the Sustainable Agriculture Research and Education (SARE) program. Funded by the USDA National Institute of Food and Agriculture (NIFA), Southern SARE operates under cooperative agreements with the University of Georgia, Fort Valley State University, and the Kerr Center for Sustainable Agriculture to offer competitive grants to advance sustainable agriculture in America's Southern region.