Another Pest of Pollinators: Small Hive Beetle Management in Honey Bee Colonies
By David Coyle, Ph.D.
There’s been a lot of attention given to pollinators recently, especially native pollinators—which include bees, wasps, flies, beetles, and several other organisms—but also those species used commercially. Yes, I’m talking about European honey bees, (Apis mellifera). Their colonies are often moved great distances and are essential to produce many food crops. Like ’em or not, European honeybees are a critical spoke in the agricultural wheel.
Unfortunately, as with any commercial species, there are pest issues. Varroa mites and colony collapse disorder are probably the two problems that most folks are familiar with, but a new article published in March in the open-access Journal of Integrated Pest Management profiles another pest: the small hive beetle (Aethina tumida).
Small hive beetles can cause millions of dollars in damage annually to honey bee hives, say the authors of the article, Virginia Tech’s Morgan Roth, James Wilson, Ph.D., and Aaron Gross, Ph.D. Native to sub-Saharan Africa (and first observed in Florida in 1998), this invasive species feeds on honey bee eggs and larvae as well as the honeycomb and pollen. Larval frass results in increased growth of a fungus that causes fermentation and creates a slimy substance in the hive. A single female beetle can lay up to 2,000 eggs, so populations can increase very rapidly.
Even though adult honey bees try to defend their hive, these beetles have evolved several different ways to avoid attack. They run, hide, and drop from wherever they are, and they even pull their legs underneath their body like a turtle. Sometimes, adult beetles even trick adult honey bees into feeding them by touching their mandibles with their antennae!
Management of small hive beetles isn’t easy, as both adult and larval beetles cause damage, and the life cycle is split between inside and outside the hive. (Larvae leave the hive to pupate in the surrounding soil.) Also, there isn’t an established economic threshold, so treatment tends to be whenever the apiculturist thinks it’s necessary. Several treatment methods are used, including cultural ones (e.g., managing hive humidity, treating the surrounding soil with diatomaceous earth or lime), maintaining proper apiary sanitation, in-hive trapping for adult beetles, chemical control methods, and biological control (e.g., predaceous nematode releases to target beetle pupae). Recently, scientists have also been testing the use of RNA interference techniques as a management method.
The last thing we need is another invasive species wreaking havoc on our agricultural system, and in this case there is a lot we still need to learn about small hive beetle management. However, the good news is that effective management options are out there to help protect this important agricultural asset.
Journal of Integrated Pest Management