Asian hornet expansion poses risks via large secondary nests

The invasive Asian hornet (Vespa velutina) is expanding its presence, with experts highlighting the critical transition from small primary nests to large secondary nests. During the summer months, approximately 70 percent of colonies move from small, ground-level nests to much larger secondary nests located 10 to 30 meters high in tree canopies. These secondary nests can reach up to 1.20 meters in diameter and house between 3,000 and 5,000 hornets.

In regions such as Lower Saxony, Germany, the presence of these hornets has become a regular occurrence. Experts warn that the species is highly aggressive, particularly when defending nests, and poses a threat to honeybee populations by hunting them in flight. The stings are reported to cause significant pain and release a signal substance that attracts other hornets to the area.

To manage the spread, specialists recommend identifying early-stage nests in sheds or under eaves before the colony moves to the canopy. Once a secondary nest is established, the population grows rapidly as hundreds of new queens develop. Authorities advise the public to report sightings through official portals and to maintain a distance of at least 10 meters from any detected nests.