The yellow-legged hornet has arrived in New Zealand, and it's a terrifying prospect. But don't panic just yet; there's a way to stop this deadly invader in its tracks. Imagine a tiny, winged terror with a sting that could spell disaster for New Zealand's ecosystems and even put lives at risk. This is the story of the yellow-legged hornet's arrival and the urgent need to halt its spread.
The recent discovery of nests in Auckland has sparked concern among experts, with Victoria University's ecology professor Phil Lester urging everyone to take action. This hornet is not one to be taken lightly, as it has already caused significant issues in Europe. And here's where it gets controversial: despite its small size, this hornet packs a powerful punch.
So far, there have been five confirmed sightings, including two small nests over a kilometre apart, indicating a potential widespread presence. But why is this such a big deal? Well, the yellow-legged hornet (Vespa velutina) is an aggressive predator with a taste for honey bees and a knack for rapid colonization.
After its accidental introduction to France in 2004, it spread like wildfire, covering 100 kilometres annually and establishing itself across the country by 2017. It has since conquered Spain, Portugal, Germany, and other European nations, with its predicted range extending as far as Scotland in the UK. And this is the part most people miss: the hornet's success in Europe hints at its potential to thrive in New Zealand's diverse environments.
In some European regions, densities of up to 13 nests per square kilometre have been recorded, each housing thousands of workers, with some nests reaching a staggering 13,000 individuals. But the real danger lies in its impact on people and pollinators.
Hornet stings can be deadly, and these insects will fiercely defend their nests, attacking people from hundreds of metres away. In Europe, they are a leading cause of anaphylaxis, with multiple stings potentially causing multi-organ failure. Even well-intentioned attempts to destroy nests can result in eye injuries, as hornets can spray venom through beekeeping suit visors.
To make matters worse, honey bees are a significant part of their diet. A European study revealed that 40% of their prey were honey bees, 30% flies, and the rest included other wasps and pollinators. In some areas, beekeepers have suffered devastating hive losses, with reports of up to 80% loss once hornets establish themselves. More commonly, losses cluster around 30%, forcing beekeepers to resort to desperate measures, such as swatting hornets with badminton rackets.
These hornets prey on tired bees returning from foraging trips, causing bees to stop foraging altogether and leading to 'foraging paralysis.' The yellow-legged hornet endangers both native and introduced pollinators and the vital process of pollination itself. Beekeepers in the UK are particularly concerned, with record nest numbers reported this year, even as far north as Yorkshire.
A single nest can consume around 11 kilograms of insects in one season. New Zealand's unique vulnerability lies in its lack of co-evolved defenses against social hornets and wasps. Our native insects are unprepared for this threat, and our warm, temperate climate provides an ideal breeding ground. If established, hornets could become widespread and highly destructive.
However, there is hope. Quick action is crucial for eradication. While invasive hornets and social wasps are challenging to eliminate, success stories exist. The United States successfully eliminated the giant Asian hornet (Vespa mandarinia), and Germany wasps were eradicated from the Chatham Islands. Even Spain temporarily celebrated the eradication of the yellow-legged hornet from Mallorca, although populations have since reappeared.
The secret to success? Acting early. Citizen science has been instrumental in detecting and eradicating invasive species, including these hornets. We must find and destroy their nests early in the year, before new queens and males emerge in autumn. Public trapping and reporting have proven effective overseas, and New Zealand's tradition of public vigilance can be a powerful tool.
Traps designed for yellow-legged hornets in Europe could be implemented here, but even homemade traps made from plastic drink bottles can work. These hornets are attracted to various spring foods, including protein and even beer. New Zealand's commitment to protecting its unique biodiversity can make a real difference.
Report any sightings online or via the exotic pest hotline. Together, we can stop this invader and protect our precious ecosystems. But the question remains: will New Zealand's swift action be enough to halt the yellow-legged hornet's march?
