Beekeeping Under Threat

They are already in our backyards.

Apiary Defensive Practices Against Vespa velutina in South Carolina

Hey y’all, we all love the satisfaction of tending thriving hives and harvesting that golden honey. However, a serious challenge has arrived in our region. As you know the yellow-legged Asian hornet (Vespa velutina) has established a foothold in the United States. In 2025 alone, reports indicate more than 80 nests across our state—a sharp increase from just 16 the previous year—with confirmed sightings in York County, the Lowcountry, and indications of further expansion. Despite dedicated work by Clemson University's Department of Plant Industry (DPI)—including contributions from experts like Brad Cavin and Ben Powell, who are leading monitoring and response efforts—eradication has not been achieved. Containment, given the hornet's rapid reproduction and adaptability, seems unattainable. Once established throughout South Carolina’s 32,000 square miles, managing reported nests could cost an estimated $4.2 million plus annually at approximately $120 per nest, with limited, if any, long-term benefits. There are about 400 acres of woods and swamp behind my place and I’d challenge anyone to find the proverbial needle in that hay stack.

That said, we are far from defenseless. Relying primarily on Andrew Durham's in-depth book, *Asian Hornet: The Beekeeper's Guide*, which draws from extensive European field experience by a seasoned UK beekeeper, this post provides a practical defense strategy. In areas with heavy infestations, these approaches have limited colony losses to under 10%. The key is to act promptly, before the hornets become more widespread in our area. Below, we outline strategies adapted to South Carolina's climate, with temperatures in °F and measurements in imperial units for straightforward application. Together, we can protect our hives and keep our bees productive.

Understanding the Threat

Consider this: A single nest can produce 6,000–10,000 hornets in a season, consuming more than 24 pounds of insects, including our honey bees. Predation intensifies from June through November, with hornets capturing bees in mid-flight. This leads to "forage paralysis," where as few as 4 hornets can reduce foraging by 40%, 6 by 60%, and just those few can actually halt it completely, causing bees to deplete their stores early and weaken the colony. In the fall, during critical winter bee production, vulnerable hives may face direct invasions, resulting in significant losses.

The stings of the “Bee Hawk” as Ben Powell calls them, are particularly concerning. The venom includes 300 components, some akin to those in sea snakes, which can heighten the risk of anaphylaxis. As beekeepers, our frequent exposure places us at greater risk. Additionally, Vespa velutina's presence pressures native species, such as European hornets, to prey more heavily on bee colonies, compounding the impact on our apiaries.

While this is alarming, preparation is our best ally. In South Carolina's mild winters, queens may emerge by mid-February when daytime highs reach 55–60°F for several consecutive days.

1. Early Detection and Monitoring: Your Hive's Early Warning System

Proactive monitoring allows us to identify threats before they escalate—much like a vigilant watch over our apiaries.

- Begin in January or when daytime highs consistently reach 55–60°F for several days.

- Install 1–2 selective traps per apiary (or one per 5–10 hives), positioned 3–6 feet above the ground and 30–65 feet from the hives to avoid attracting hornets closer.

- Clemson’s Brad Cavin has a video on how to make traps and what to mix as bait that you can view [here]. Avoid using honey in your bait to prevent risks such as foulbrood.

- Inspect traps weekly, and report any Vespa velutina captures immediately to Clemson DPI using their [yellow-legged hornet reporting tool].

- In the fall, as foliage thins, inspect trees for visible nests.

2. Spring Trapping of Queens: Prevent Nests from Forming

Targeting queens in spring can reduce nest establishment by over 90% in monitored areas—a highly effective early intervention.

- Implement from mid-February to mid-May, placing 4–6 protein-baited traps along the apiary perimeter (within a 1/3-mile radius).

- Suspend traps 6–10 feet high in sunny trees or on posts, spaced 65–165 feet apart for optimal coverage.

- Effective baits include canned cat food (beef or fish varieties), sardines in oil, or fish scraps combined with sugar syrup. Refresh every 3–5 days, as our humidity and warmth accelerate spoilage.

- Some selective designs, such as bottle traps with inverted funnels or commercial Vespa Catch models, feature escape holes to protect beneficial insects.

- Discontinue when native yellowjackets and European hornets predominate in catches (typically late May in South Carolina). Focus on selective methods to preserve our local ecosystem, where Asian hornets comprise only 1–2% of captures.

3. In-Apiary Physical Barriers: Strengthen Defenses During Peak Predation (June–November) As hawking activity increases, physical protections enable bees to forage while deterring hornets.

- **Entrance Muzzles**: Attach 1/2-inch hardware cloth muzzles (with 0.5-inch square gaps) extending 4–6 inches outward. This allows bees free movement while blocking hornets. Durham's book offers simple DIY instructions.

- **Electric Harps**: Install a grid of fine stainless-steel wires (0.006–0.02 inches thick, spaced 0.8 inches apart) 4–6 inches in front of the entrance, powered by a 12V solar fencer (1,500–3,600 volts, low current). Hornets contacting the wires are stunned and collected in soapy water below. Field studies demonstrate captures of dozens per day, significantly reducing predation. (***Now here I think there is some opportunity to reinvent the wheel. For hobbyists who only have a few hives and a penchant for woodworking these DIY zappers might could be useful, but for folks with dozens? The cost of about $100 per hive in materials and the sweat equity required to MacGyver them up is prohibitive, and given that this pest is going to become a national problem I firmly believe that someone with an engineering bent could whomp something up that is easy to deploy and much cheaper. 2¢.)

- Narrow entrances down to the small openings on your reducers.

4. Hive Management and Colony Strength: Foster Resilient Colonies

Robust hives are better equipped to withstand threats—prioritize health throughout the year.

- Supplement with 1:1 sugar syrup if natural nectar is insufficient, in our area we really never don’t have some sort of pollen available for our bees to bring in, and small hive beetles surely do love pollen patties.

- Grouping hives in clusters (at least 5 together) rather than dispersing them, can help distribute predation pressure. But, it can also contribute to horizontal disease vectoring where bees walk in the wrong door and drop off a varroa mite or three.

- Select defensive strains, such as Carniolan, Russian, or locally adapted survivor bees.

- Minimize attractants: Conduct inspections at dawn or dusk, perform extractions away from apiaries, and maintain low varroa levels (avoid vaping during active hornet seasons, as it may draw them).

- In cases of severe pressure, combine weaker colonies or temporarily seal hives to allow recovery, internal feeders with 1:1 or 1.5:1 sugar syrup would help maintain and protect their collected stores from being consumed and inspire brood building to recoup some of the bees lost to predation.

5. Nest Tracking and Destruction: Locate and Report Sources

Upon observing hawking hornets, trace them to enable professional intervention.

- Establish a tracking station 100–200 feet from hives using a dish of shrimp or tuna.

- Capture a hornet, mark it with flour or non-toxic paint, release it, and observe its direct flight path to the nest. Use multiple stations for triangulation.

- Once located, provide precise GPS coordinates to Clemson DPI via their [yellow-legged hornet reporting tool] -removal is provided at no cost. Avoid self-destruction; hornets defend aggressively within 30 feet, using 1/4-inch stingers capable of multiple strikes.

- Note: Primary Spring nests are smaller and lower; secondary summer and fall nests are larger and often concealed higher in trees.

Recap

- **Jan–Feb**: Initiate monitoring traps when highs consistently reach 55–60°F.

- **Mid-Feb to Mid-May**: Deploy 4–6 protein traps (fish or cat food) within 1/3 mile; position 6–10 ft high, 65–165 ft apart; refresh bait every 3–5 days.

- **June–Nov (Peak Predation)**: Install 1/2-inch hardware cloth muzzles OR electric harps 4–6 inches from entrances; reduce to 2 in × 3/8 in; consider grouping under 16 × 16 ft mesh canopy.

- **Colony Strength**: Provide Spring feeds of 1:1 syrup and pollen; cluster hives; choose defensive stocks.

- **Hornet Sighting?**: Capture, mark with flour, track, and report GPS to Clemson DPI via their [reporting tool]—do not attempt removal yourself.

- **Conclude Protections**: Discontinue when nights fall below 50°F for a week (typically mid-November in South Carolina).

By integrating early trapping, reliable barriers, and strong colonies, losses can remain below 10% even in affected areas. Remain vigilant, report all sightings, and adjust as conditions evolve. It is worth reiterating that this pest will become a nationwide concern, given its demonstrated adaptability to northern latitudes and diverse habitats—from the tropics of Southeast Asia to the UK, China, South Korea, and beyond. These hornets are here to stay, but our bees—and our community—are resilient.

For further reading, consult Durham's book on [Amazon] or contact Clemson DPI. The book has way more material than I covered here and is well worth the read.

Kelly Davis

Certified Beekeeper

ACBA Webmaster