Asian hornet: the European bee-eater as a natural garden ally

In many gardens across German-speaking parts of Europe, the Asian hornet has become a recurring concern every summer. These insects crowd patios, buzz around people’s heads and, above all, place immense pressure on beekeepers. Although many homeowners instinctively turn to traps or poison, current conservation reports point to a far more effective helper already flying overhead – one that works entirely free of charge.

Asian hornet: why pressure in the garden is increasing

The Asian hornet (Vespa velutina) is regarded as an invasive species in Europe. Originally native to Asia, it has spread from France into several countries since the 2000s. Increasing numbers of sightings are now also being reported in regions of Germany and Switzerland.

A single nest can consume more than 11 kilograms of insects in one year. A substantial share of this consists of honey bees and other pollinators. This creates difficulties for beekeepers and reduces pollination of fruit trees, vegetable crops and wildflowers.

“An Asian hornet nest can produce several tens of thousands of workers in a season – enough to noticeably change an entire region.”

Many gardeners respond by using alcohol-based traps or insecticides. While these solutions are quick to set up, they usually catch or kill anything that enters them: solitary bees, hoverflies, beetles and butterflies. Rather than reducing hornets alone, they remove an important part of the local insect community. Yet this diversity is precisely what natural predators need in order to find sufficient prey.

The unexpected ally: a colourful insect hunter

Conservationists therefore point to a predator that many people have seen without consciously noticing it: the bee-eater, more precisely the European bee-eater (Merops apiaster). This migratory bird arrives here from Africa in summer and remains until late summer.

Its plumage is striking, combining turquoise, yellow and rusty brown with a distinctive black eye stripe. It can often be spotted on telephone wires, dry branches or the tops of dead trees, using these perches to launch attacks on insects in flight.

Research by bird conservation organisations and natural history museums shows that this bird’s diet consists mainly of hymenopterans – insects such as wasps, bumblebees, bees and hornets. On warm days, one European bee-eater can catch around 70 to 80 insects of this kind.

“Where bee-eaters hunt regularly, the number of troublesome wasps and Asian hornets in the immediate area falls noticeably.”

The bird can be found here from around mid-May until the end of August. This is exactly the period when activity in hornet nests rises sharply, making the European bee-eater a perfectly timed opponent.

How the European bee-eater handles hornets without risking a sting

Its hunting method is remarkably precise. First, the bird spots an insect while it is airborne. It then makes a short, swift approach and catches it with its long, slightly curved bill before returning to a regular perch.

There, it repeatedly strikes the prey against the branch or wire to stun it. The bird then carefully rubs the insect along the surface, removing the sting and squeezing out the venom. It eats the prey only once the sting has been removed. This protects the bird and allows it to consume even adult hornets safely.

How to attract the European bee-eater to your garden

Naturally, nobody can guarantee that a European bee-eater will settle in a particular garden. However, it is possible to make the location much more appealing to the bird. Observations repeatedly show that three measures are particularly effective.

• Avoid insecticides: Garden chemicals do not only kill pests; they also destroy many beneficial insects. If the food chain collapses, the European bee-eater will stay away because it simply cannot find enough prey.
• Keep tall lookout perches: Power lines, taut washing lines, tall dead branches and mature isolated trees make ideal perches. From these positions, the bird surveys the surrounding area and begins its hunting flights.
• Leave sandy banks and steep slopes undisturbed: European bee-eaters breed in tunnels that they dig themselves, often in sandy slopes, raised banks or unsealed embankments. Where every surface has been levelled and sealed, they cannot find a nesting site.

An open area with water is also useful. A shallow clay dish, set slightly into the ground in an unobstructed spot, is enough. European bee-eaters often drink while flying past, skimming just above the water’s surface.

A practical example from a heavily affected area in south-western Europe illustrates how straightforward this can be. A property owner left a dead tree standing at the end of the garden and stopped using sprays. A pair of European bee-eaters used the tree as a lookout point throughout the summer. Hornet activity around the patio declined noticeably, and the family was once again able to eat outdoors without being constantly attacked.

European bee-eaters and beekeeping: competition or useful partner?

The name bee-eater understandably makes many beekeepers uneasy. The bird does indeed eat honey bees. However, evidence from long-term observations shows that the proportion of honey bees in its diet varies and is generally far below the number destroyed by a hornet colony over the same period.

The European bee-eater hunts a wide variety of prey, including:

• Asian and native hornets
• Various wasp species
• Broad-winged flying insects such as horseflies
• Bumblebees and other solitary bees
• Large butterflies and beetles, depending on availability

For many beekeepers, the local benefit outweighs the drawback. The number of attacking hornets visibly falls in the flight path in front of hives when European bee-eaters regularly hunt nearby. This eases the strain on weak or already stressed colonies.

“The bee-eater may take individual honey bees, but at the same time it checks the pursuers that place entire colonies under pressure.”

Nevertheless, the bird is not a substitute for professional action. If a large Asian hornet nest is located directly on a house, at a school or close to an apiary, a trained specialist company should be called in. Many regions operate reporting points or online platforms through which such sightings are recorded and coordinated.

Why traps and poison often cause more harm than good

From a human point of view, homemade traps can seem appealing: they are quick to make, filled with a sweet attractant, and soon dozens of insects are floating inside the container. In reality, however, they mainly catch harmless species or even species that are strictly protected. These are the very insects needed to establish a stable balance in the garden.

Poisons create another problem, as many active substances are non-selective. They also harm caterpillars, solitary bees, beetle larvae and aquatic organisms when washed away. Once diversity disappears, hardy problem species that have become resistant to the products ultimately gain the upper hand.

By contrast, the European bee-eater works like a targeted seasonal “task force”: it hunts only what it can catch, does not harm plants or soil organisms, and automatically adjusts its activity to the insects available.

Background: invasive species and natural predators

The Asian hornet demonstrates how severely an ecosystem can be destabilised when a new species arrives without its original predators. In its native range, specialised parasites, birds and other predators keep it in check. Many of these natural opponents are absent in Europe.

The European bee-eater fills this gap only in part, as it hunts opportunistically and only during summer. Even so, its role highlights the value of intact food webs. The more varied the insect and bird species living in a region, the less likely it is that one species will dominate the entire system.

Practical tips for a bird-friendly, hornet-safe garden

Anyone wishing to create a garden that is both rich in insects and pleasant to use can achieve a great deal with a few measures:

• Create flowering areas with native plants used by solitary bees and hoverflies.
• Avoid closely mown ‘carpet lawns’ and allow selected areas to grow taller.
• Deliberately retain old branches, deadwood and individual dead trees as structural features.
• Provide water sources that are shallow and clearly visible.
• Remove poisons and indiscriminate killing traps from the garden.

This creates a setting in which not only European bee-eaters, but also other insect hunters such as swallows, bats and various wasp species can play their part. Together, they can reduce the day-to-day pressure caused by the Asian hornet to a manageable level.

So, when the deep buzz of a hornet is heard on the patio again in summer, it is worth looking upwards. Perhaps the most important helper is already sitting on the nearest branch, merely waiting for its opportunity to strike – with no bill to pay, no poison and an impressive aerial display included.