The Association of Beekeepers of the Balearics (ABA) is launching a project to install sentinel apiaries at the port of Palma, aiming for early detection of invasive wasps arriving on goods or vessels to Mallorca. This initiative targets two species of concern: the Asian hornet (Vespa velutina), widespread across northern Spain, and the oriental hornet (Vespa orientalis), predominantly found in southern Spain. Both have already been identified in the Balearics, most likely arriving hidden in cargo or yacht sails during hibernation months.
Once these wasps complete their journey, they emerge to reproduce and continue their life cycle. A single Asian hornet queen can lay up to 200 new queens, highlighting the critical need for prompt identification and control measures. Garrit Parra, president of the ABA, details a pioneering effort introducing a new type of trap to the islands designed specifically to locate these invasive wasps threatening local bee populations and broader biodiversity.
The Balearic Agriculture Department and COFIB located and removed 21 Vespa velutina nests in 2025. This Asian hornet species was responsible for three fatalities in Galicia within two weeks due to stings sustained during outdoor rural work. In 2024, a Vespa orientalis nest was destroyed in Esporles, with sightings in Cala Major and Selva though no nests were found there. "These figures confirm the ongoing threat, requiring our full attention," said Parra. He warns that including fertilised queens currently hibernating, the risk of new nests is imminent.
New traps to improve detection in the Balearics
While traps used to catch Vespa velutina have had some success, trials of over 100 lures for the Oriental Hornet in Malaga and Jaen have failed, suggesting it is not attracted to liquid baits. In response, Balearic apiarists plan to deploy the Koldo trap, mechanically designed by Basque beekeeper Koldo Belasko. Unlike liquid traps, this model requires no bait and could be effective against the Oriental hornet.
The team is constructing apiary traps from recycled shelving and 0.8 mm mesh, resembling fishing nets. These will be placed in front of beehives so that wasps chasing bees enter the trap but cannot exit. "Bees are around half the size of wasps; the structure features a funnel-shaped entrance positioned before the hives. Once a wasp enters, it cannot get out," Parra explained.
Challenges of invasive wasps in urban and rural settings
Parra pointed out that the first Oriental hornet recorded on Mallorca likely arrived on a sailing boat at Soller. Understanding their life cycle is critical to controlling their spread: in winter, only fertilised queens hibernate, seeking sheltered spaces such as tree trunks, yacht sails, or cargo containers. Apiculturists regularly detect invasives when they raid hives, but legal restrictions ban intensive beekeeping in urban areas, limiting data on wasp presence in Palma, a potential hotspot for unnoticed nest establishment.
"A Oriental hornet nest was discovered in Palma for the first time last year," Parra noted. "Large, mostly unused buildings such as the cathedral or Almudaina could easily harbour nests without detection. If an invasive colony establishes and remains unnoticed this year, next year there could be 200 more nests, since one queen can produce up to 200 new queens annually." The proposal to install sentinel apiaries depends on cooperation between the regional and central governments to relax urban beekeeping regulations as a public health measure.
"Even if just one or two invasive queens are caught yearly in the traps, it would prevent between 200 and 400 new nests each season," he said. When an invasive wasp is detected in the sentinel hives at the port, the apiarists will notify COFIB, which will deploy baiting systems to track and confirm urban nesting and proceed to nest removal if necessary.
Broader ecological and public safety concerns
Experience with other pests in Mallorca, such as the red palm weevil and processionary moth, shows that once numbers exceed certain levels, eradication becomes impossible. The invasive wasps pose an even greater threat, attacking not only bees but other insects as super-predators. Besides affecting pollination and fruit crops, their presence raises safety concerns. "In October, three people died in Galicia during rural work after multiple wasp stings," warned the ABA.
Apiculturists are also engaging with the local hotel sector to slow wasp expansion, requesting donations of old iron shelving to build traps. They highlighted how the Asian hornet, now established alongside the German wasp in Mallorca, is commonly encountered around outdoor buffets and is twice the size of the latter.
ABA urges owners of rustic land near urban hotel zones or ports to grant access for setting up sentinel apiaries. While the Port Authority supports the project, the exact locations for trap installation are yet to be finalised. Discussions with the Balearic Agriculture Department are ongoing, but "we don’t know how many fertilised queens are currently hibernating, which could be establishing nests within a month," noted Parra.
The Asian hornet nests mainly in trees, hidden among branches, while the oriental hornet forms nests underground, making them harder to find. Hence, public assistance in reporting sightings to COFIB is vital for effective monitoring.
So far, invasive wasps have devastated 80% of beekeeping operations in the most affected areas of northern Spain. "Here, we don’t yet have mortality data as severe but if action is not taken, they could destroy 80% to 100% of hives," Parra concluded.