By 2021, Michel Costa, an experienced beekeeper in Bordeaux, France, had become deeply frustrated by the persistent threat of invasive Asian hornets decimating his honey bee colonies.
Costa had tried various methods to combat these hornets: using an electric racket, injecting their nests with chemical disinfectants, and even employing local hunters with shotguns to destroy nests. Despite these efforts, the hornets continued to wreak havoc.
That year, Costa learned about a new tool: “electric harps,” which claimed to kill hornets by electrocution. Intrigued, he tested one at a nearby apiary experiencing hornet issues. To his amazement, the harp effectively eliminated numerous hornets quickly. “The demonstration was astonishing,” he noted.
Asian hornets, which arrived in Europe from China in 2004, have posed a severe threat to local honey bees. They predate on bees at a rate of 30 per day, causing significant disruptions in honey production and pollination. The hornets have spread across Europe, impacting countries like France, Spain, and Italy, and recently, scientists confirmed their presence in the U.S. as well.
Beekeepers and scientists have long struggled to find effective methods to protect honey bees from these hornets. Previous methods, such as trapping queen hornets or using protective “muzzles” for hives, proved either ineffective or too costly.
Electric harps, which have been gaining traction among beekeepers, consist of a large frame with conductive metal wires that deliver an electric shock when hornets fly through them. They are placed around hives along hornet flight paths. Research shows that these harps can reduce hornet predation by up to 89%, significantly improving hive survival rates.
A key advantage of electric harps is their ability to target hornets specifically while allowing bees to pass through unharmed. Studies show that 91% of insects killed by the harps are Asian hornets, with minimal impact on honey bees.
Electric harps are relatively affordable, with kits costing around $300, and their maintenance costs are low, especially when combined with solar panels. Beekeepers, often without government support, find these harps a cost-effective solution.
Costa and entomologist Denis Thiéry, who have become collaborators, are now teaching other beekeepers to build their own harps using inexpensive materials. They recently conducted a workshop to share their design and material recommendations.
While electric harps represent a promising tool in the fight against Asian hornets, Thiéry acknowledges that no single method will eradicate the problem. Instead, a combination of strategies, including electric harps and nest removal programs, offers the best hope for protecting honey bee populations.