Biodiversity has been making headlines lately, for all the wrong reasons.
Recent sightings of invasive Asian hornets, Vespa velutina, in Cork city have sparked widespread concern about the safety of our native pollinators.
Asian hornets are formidable predators that hunt and kill other insects to feed their developing young.
Like our native wasps, they build nests and rear their larvae on a diet of invertebrates.
However, unlike native wasps, their appetite for prey is far greater, placing extra pressure on insect populations that are unprepared for this new threat.
Much of the current discussion centres on protecting pollinators from these invaders, with beekeepers among the most vocal and understandably worried. Yet the arrival of the Asian hornet also offers an opportunity to reflect on the true diversity of our pollinators, which includes far more species than many people realise.
Pollinator populations
Bees, butterflies, moths, and hoverflies are considered our most important pollinator groups. In Ireland, there are thought to be approximately 1,500 species of moth, 180 species of hoverfly, and 103 species of bee. Only one of these, the honeybee Apis mellifera, produces honey, and it is this species that dominates much of the debate around preventing the spread of the Asian hornet.
It is true that honeybees are under threat. The Asian hornet has had a devastating impact on hives and beekeeping across Europe, with serious economic consequences for the honey industry. One hornet can kill up to 50 bees a day, wiping out entire hives.
In many areas this has forced people to abandon commercial apiaries or give up beekeeping as a cherished pastime.
It is encouraging that public concern and economic interest are driving action, since preventing the establishment of the Asian hornet will protect not only honeybees but also the many other insects it preys upon. Aside from the honeybee, Ireland’s other 102 bee species include 21 bumblebees and 81 solitary bees.
Dietary studies
Research shows that although honeybees form an important part of the Asian hornet’s diet, these invaders are highly adaptable and by no means selective. Few invertebrates are safe. A recent analysis (Pederson et al., 2025) of the gut contents of Asian hornet larvae collected from Jersey, France, Spain and Britain revealed remarkable dietary variety. The hornets were found to consume bees, wasps, flies, beetles, butterflies, moths and spiders. In total, 1,449 species and species groups were
identified.
Of the 50 most common prey, 43 were pollinators, including four of Ireland’s widespread bumblebee species. Alarmingly, pollinators were not the only group at risk. Insects with crucial roles in decomposition and nutrient cycling, such as the yellow dung fly, as well as native wasps that help control pest numbers, were also targeted.
Researchers concluded that the Asian hornet has the potential to disrupt entire ecosystems, not just honey production.
Nice newbies
Several new bees, or ‘newbies’ if you like, have arrived in Ireland in recent years. Among them are the hairy-footed flower bee (2022), the ivy bee (2021) and the tree bumblebee (2017). Unlike the invasive Asian hornet, these species have arrived naturally, expanding their range as the climate changes, and they pose little threat to local wildlife. The Asian hornet, by contrast, was introduced accidentally. It is thought to have arrived in a shipment of pottery from China to France in 2004, and it has been spreading across the continent ever
since.
The arrival of these new bee species is unfortunately offset by the decline of many native Irish bees, now threatened with extinction because of habitat loss, pesticide use, disease, and the impacts of climate change. The great yellow bumblebee, for example, is on the brink of disappearing from Ireland.
The last thing these vital and charismatic pollinators need is an additional pressure such as a predator like the Asian hornet tipping the balance further against their survival.
What you can do
Guidance is available on websites such as pollinators.ie on how to create insect-friendly gardens. Insects rely on native plant species; non-native and invasive plant varieties are of little value to their survival.
Therefore, it is key to plant and encourage native plants and manage non-native and invasive species on your land. Strictly limiting the use of insecticides and herbicides is vital.
You can consider joining a citizen science survey to help monitor insects. Examples include the Bugs Matter Citizen Science Survey, recently introduced to Ireland, and the All-Ireland Bumblebee Monitoring Scheme.
Other useful actions include buying organic and locally sourced fruit and vegetables where possible, and encouraging children to value insects rather than fear them, helping to avoid a ‘kill it’ culture in future generations.
Tipping point
Crucially, we should all learn how to identify an Asian hornet and report any sightings to the National Biodiversity Data Centre. More information can be found at invasives.ie.
It is difficult to predict how prolific or harmful the Asian hornet might become here, but evidence from other countries is far from reassuring.
Following the first sightings, the government of Ireland has launched a biosecurity alert to determine if there is an Asian hornet
population.
Is the Asian hornet the greatest threat to our native insects? It is a severe danger to apiculture and beehives, but for wild insects it is one of many pressures and perhaps not the most serious.
Yet when added to habitat loss, other invasive species, climate change, pollution and pesticides, it is an unwelcome additional burden that places our fragile ecosystems, in which insects are fundamental, at ever greater risk.
