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Honey bees defending the hive by surrounding an invading wasp.

The hot topic in the news right now is two verified reports of Asian giant hornets (Vespa mandarinia) in Washington state in December 2019. These hornets are a hunting species from eastern Asia. As discussed in Asian Giant Hornets Not in Alabama, currently Washington state is the only location where specimens have been found. The Alabama Department of Agriculture and Industry Pest Protection Unit and the Alabama Extension Plant Diagnostic Lab both confirm that at the moment there are no confirmed reports of Asian giant hornets in Alabama.

In their native ranges, Asian giant hornets hunt other social wasps, bees, and large beetles to feed their larvae. The discovery of these hornets has many beekeepers on alert, as honey bee colonies are a big food source for these hornets.

Hunting Strategies

Asian giant hornets have two main hunting strategies they use against honey bees.

  • Individual attacks. Individual hornets may attack honey bees at the hive entrance. They will bite off the head and abdomen and fly away with the thorax to feed to their young. The thorax is where a bee’s flight muscles are located, making it the meatiest part of the bee.
  • Group attacks. In some cases, particularly in the fall, a group of hornets will stake out the landing board of a hive and begin what entomologists term as a slaughter strategy. They will decapitate bee after bee to decimate the population of the hive, usually within a day. After killing most of the adults, the hornets will begin taking the larvae, pupae, and honey supplies to their colony to feed their young.

Colony Under Attack

While there are no known Asian giant hornets in Alabama, there are other wasps and hornets that can also attack a colony of honey bees. There are a few things beekeepers should keep in mind if their colonies come under attack.

Reduce Hive Entrances

To help a colony defend against local honey bee predators, beekeepers can narrow the entrances to the hive using entrance reducers or other material. This allows the guard bees a better chance to defend the colony. This is the same thing beekeepers do to prevent robbing behavior. This is a good tactic to use in mid-summer and fall during the nectar dearths, when honey bee colony populations are down, while predator wasps and hornets have larger populations.

Some beekeepers advise the use of queen excluder screen over hive entrances. However, this is not an effective strategy to protect against Alabama’s local honey bee predators.

Maintain a Healthy Colony

Honey bees defending the hive by surrounding an invading wasp.

Honey bees defending the hive by surrounding an invading wasp.

Asian species of honey bees can defend themselves against Asian giant hornets. These honey bees will surround and kill the hornets that get into the colony. Masses of worker bees will sacrifice themselves to kill the invader by completely covering the hornet, and furiously working their wing muscles to generate heat. The heat in the center of the ball of bees will rise to the point where it kills the hornet.

While western honey bees (Apis mellifera) – the species that we have in the United States – have a somewhat similar behavior, they are not as effective as Asian honey bees. Instead, western honey bees appear to rely more on stinging, which is effective on smaller predator species. This make it all the more important for beekeepers to maintain a heathy and large worker population so they can defend themselves. A full colony is a happier, healthier, and better defended colony.

The video below shows honey bees fighting off a yellow jacket invader. Yellow jackets and hunting wasps are the more likely danger to honey bees in Alabama.

 

Insect Identification

If a beekeeper finds an insect in or on a hive and needs help identifying it, Alabama Extension can help. Under current COVID-19 conditions, agents aren’t available for in-person identification, but they can help with identification via text message or emailed photographs. Visit the Alabama Extension directory to find the contact information for the Extension agents in your area.

Submitting a Specimen

If beekeepers need to submit an insect specimen for identification, there are certain steps they must follow.

  • Visit the Plant Diagnostic Lab website or contact an Alabama Extension professional for information on the form and payment that have to be sent with the specimen. See the Forms section of the diagnostic lab website to download the proper form.
  • Place the insect in a vial or small jar and fill it with standard rubbing alcohol to preserve the insect. If a small jar or vial is unavailable, place the specimen in a box (with no alcohol). The goal is to keep the insect from being crushed in the mail.

For more information about submitting specimen or other services the diagnostic lab offers, visit the Plant Diagnostic Lab website.

Stay Vigilant

Beekeepers play an important role in the protection of honey bees. That is why it is important that they stay involved in the monitoring of potential pests. Beekeepers should check colonies and report problems to the Apiary Inspection Unit and Alabama Extension. By working together, beekeepers keep Alabama’s honey bees safe and healthy.

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