This page provides information and links about Asian hornets, which have the potential to decimate our hives. They've not been sighted in NW Georgia yet, but their population is increasing rapidly.

Learn more:

Georgia Department of Agriculture site for education and reporting nests

A gifted article from the New York Times on the Asian Hornet invasion in South Carolina. The Georgia Beekeepers Association has provided educational resources to our club to help us be alert and be ready for these nasty critters.

The same book on Asian Hornets and what British Beekeepers learned from France that GBA gifted the club. A summary of key points from the book is below. 

Information from UGA's bee program on Asian hornets

Video from Kamon Reynolds interviewing Richard Noel of France who is on the front lines with the Asian hornets

Summary of the book, Asian Hornet : The Beekeeper's Guide to Defences Against the Yellow-Legged Hornet Vespa Velutina

Asian Hornets: What Beekeepers Need to Know

These are summary notes for club members, based on lessons learned from French and Belgian beekeepers who have been dealing with Asian hornets for over 20 years. Derived from the book “Asian Hornet : The Beekeeper's Guide to Defences Against the Yellow-Legged Hornet Vespa Velutina”, which was gifted to the club from the GBA.

The Big Picture

France has been fighting Asian hornets for more than two decades, and their experience is a valuable guide for us. Colony losses are worst during the "establishment phase", the early years after hornets show up in a new area.

At this point, prevention is no longer an option. The hornets are here, and our goal is to delay how fast they get established and reduce the damage they cause.

To do that, beekeepers need to:

• Understand the threat and how hornets interact with honey bees
  
• Know how, when, and why to use different defenses
  
• Keep colonies big and healthy going into late summer
  
• Stay educated, alert, and active

Hornet activity depends on weather, not the calendar, so timing will vary year to year. Beekeepers should expect to lose some colonies, stay flexible, and be willing to experiment with new practices. Staying connected with other beekeepers to share the latest information is key.

Beekeepers are often the first to notice hornet activity, which makes us an important part of finding and destroying nests.

A Safety Warning

Asian hornets will defend their nests aggressively and can attack as a group, causing serious harm to people. This isn't something to take lightly; there is more on human health risks below.

Which Bees Handle Hornets Best?

Some evidence suggests that more defensive bee types fare better against hornets. Apis mellifera mellifera (the dark European honey bee) appears to hold up better than Italian, Caucasian, and Carniolan bees. This doesn’t mean that we should be changing the bees that we’re keeping, but good to know if your bees are at higher risk. 

Which Apiaries Are Most at Risk?

More likely to be affected:

• Apiaries near rivers or other bodies of water

• Urban and suburban areas (hornets seem to favor these, though maybe not as much as commonly believed)

• Areas with pastures and fruit orchards, since more food supports bigger nests

Less vulnerable:

• Forested areas (scientists don’t really understand why)

• Areas with intensive row-crop farming, since fewer insects (prey) survive due to habitat loss and pesticide use

It's also worth considering how many other apiaries are near yours. If nearby beekeepers aren't aware of the hornet threat or prepared for it, their hives may act as "decoys" that draw hornets to the area.

Hornet populations will likely build up slowly overall, but expect occasional surge years.

A note on sources: Not all hornet research is equally reliable, so beekeepers should stay alert for good versus bad science. Universities that are considered trustworthy sources include UGA, Clemson, University of Florida, Auburn, and Mississippi State. Researcher Randy Oliver and regional expert Kamon Reynolds is also considered a trusted source.

Data on hornet spread is incomplete partly because many beekeepers don't respond to surveys.

Human Health Risks

• Away from the nest, hornets are generally not aggressive and will only sting if handled.
  
• When hornets are robbing a hive, they will defend themselves aggressively.
  
• Hornets can spray an irritant that is very painful to the eyes. Eye protection is critical when dealing with aggressive hornets. Do NOT attempt to remove nests by yourself. Report the nest to the Georgia 
  
• Nests are usually built high in trees at first, but eventually may be built lower, under 15 feet off the ground. Nests at this height fall within the hornets' "circle of defense" and are especially dangerous to approach.

Is the risk to human health greater with Asian hornets? Several factors point to yes: they're more aggressive, there tend to be more nests, and nests are often located where people are likely to encounter them.

• In Spain, epi-pens have been distributed proactively to at-risk residents.
  
• People who are already reactive to bee venom appear to be at greater risk.
  
• Asian hornet venom is complex and shares some components with sea snake venom. In places where the hornets are established, medical studies show their venom causes more serious health problems than bee stings or stings from other hornet species.
  
• Beekeepers who have built up tolerance to bee stings do not appear to have that protection carry over to hornet stings.
  
• Epi-pens are not foolproof. Remember that most failures happen due to human error, so know how to use one correctly.
  

How Hornets Attack Honey Bee Colonies

Good years for bee colonies tend to also be good years for hornets. Hornet population growth can start as early as March and continue through November, with a sharp increase starting in August.

Hornets hunt by smell and look for concentrated sources of prey. They will "hawk" (hover and patrol) outside a hive entrance, picking off bees that are out on their own.

Just the presence of hawking hornets stresses a hive, causing bees to forage less and eat more of their stored honey. Research suggests that as few as 4 hornets hawking around a hive can cause "foraging paralysis," where bees become too afraid to leave.

Predation timeline:

• Starts in July
  
• Increases significantly in late August and September
  
• Peaks in October
  
• May continue into November
  

Hawking alone will usually weaken a hive but not destroy it. Colonies can starve from eating through their stores too fast. This can be prevented by leaving enough honey in the hive or supplemental feeding. However, this is a trade-off: the smell of honey can also attract more hornets. The stress from sustained hornet pressure can lead to colony collapse, absconding (the colony abandoning the hive), or the workers killing their own queen.

The good news: the same good beekeeping practices that keep colonies healthy also reduce hornet losses. Well-fed, healthy colonies with solid food stores hold up better.

Preparing for Peak Predation Season

1. Requeen colonies as needed
   
2. Combine weak hives into stronger ones
   
3. Consider keeping resource hives on hand to support brood-building or requeening
   
4. Make sure hives have plenty of food, either stored honey or sugar syrup
   
5. Don't forget pollen and water sources
   
6. Avoid opening hives during peak predation windows, since this can draw hornet attention
   

Trapping Hornets

• Drowning traps tend to catch a lot of "by-catch" (other insects), so use them carefully.

• If you accidentally catch European hornets (a different, less harmful species), freeze the trap for one hour instead of drowning it, then release survivors.

• To dispose of Asian hornets from a trap: empty the contents, crush the hornets, and let any other trapped insects revive and fly off. Do not rinse the trap. Leftover pheromones actually help attract more hornets.

• Spring trapping (February through late May) can help reduce the number of new nests. This is when foundress queens are out foraging on their own to start new colonies. Set traps near where nests were found the previous year.

The Four Parts of Apiary Defense

1. Apiary Environment

• Keep hives close together for safety in numbers

• Place smaller colonies or nucs in the middle of larger ones for protection

• Let grass grow long in front of and below hives. This makes it harder for hornets to hawk and gives bees a place to hide. This is different than what we usually recommend for hive beetle control.

2. Reducing Bee Stress

• Keep colonies healthy overall

• Provide water sources on or near the hive

• Reduce hiding spots for hornets: they will hide under bottom boards and pop up to grab bees. Screened bottom boards can actually increase stress by letting hornets get close to the bees.

• • Option: attach an additional box with a screened bottom underneath the hive (for example, fastened to hive stand railings) to add distance between hornets and bees.

3. Reducing Predation

• Traps are most useful early in the season

• Various trap designs exist; later in the season you'll need something that can handle higher volumes, and many designs can be built DIY

• Hive "muzzles" give bees extra space (reducing stress) while making it harder for hornets to land on the entrance board. European beekeepers have found that hardware cloth with openings of at least ½ inch works best for this.

4. Defending the Hive

Electric harp traps: A panel of fine wire mesh attached to a stainless steel frame, with small black beads on the wires used as lures. The panel sits above a pan of soapy water and is powered by a solar panel that provides continuous (not pulsed) power. Multiple panels can be connected to a single solar power source. Hornets are caught as they circle the hive hunting. The general recommendation is one harp per 5 hives, positioned perpendicular and/or parallel to the hive row.

Diana Trap: Takes advantage of hornets' poor eyesight by luring them toward a dark center spot on a small, electrified circular metal panel that sits above a pan of water. The hornet attacks the dark spot, mistaking it for prey, touches the electrified panel, is stunned, and falls into the water below.

Electrified traps like these are currently considered the most effective defense option, though they can be expensive.

Entrance restriction: Reduces the number of hornets that can invade a hive at once. A 5.5 mm opening allows worker bees to pass through but may be too small for drones.

Trojan bait: A newer method still in development, where hornets carry bait back to the nest that ultimately kills the colony.

Compiled from book reference notes. Questions about sourcing or specific techniques? Bring them to the next meeting.