The arrival of spring also heralds the return of bees, wasps and hornets humming, buzzing and droning. All three insects play an important role in nature – pollinating flowers, for example, – and they only sting when they feel threatened.
But even if you religiously follow all the safety tips, stay calm, avoid frantic movements and always wear aqua shoes in bathing areas, you’re not fully protected from being stung. It’s easy to miss the bee on the garden waste, or fall over in the exact same spot that a wasp is enjoying traces of ice cream or a forgotten piece of fruit.
Photo: Ljupco / iStock
Poisoning: Actual poisoning occurs after a large number of stings (bees, wasps or hornets) – from about fifty to several hundred stings in adults. In children, the dangerous level of insect stings for these poisoning symptoms is specified as 1–4,5 stings per kg bodyweight (Link to the study). Typically, this happens when someone (intentionally or not) disturbs a nest or is attacked by a swarm. However, these cases are extremely rare in Switzerland. In addition to a local reaction, systemic poisoning symptoms are also possible (often occurring within a few hours): Nausea, vomiting, dizziness or headaches. In severe cases circulatory collapse, epileptic seizures and multiple organ failure.
Sweet temptation – this donut clearly belongs to the wasps. Photo: heckepics / iStock
Wasps, hornets and bees are all Hymenoptera. Wasps and hornets belong to the same family (Vespidae); biologically speaking, hornets are simply large wasps. The largest native wasp species is the European hornet (Vespa crabro), which is relatively rare in Switzerland.
The common wasp (Vespula vulgaris) and the German wasp (Vespula germanica) are the main species bothering us in daily life. They are interested in human food (sweet foods, beverages, meat), which isn’t the case for the other seven wasp species in Switzerland.
Honeybee on human skin: bees only sting when they feel threatened. Photo: Ulrike Leone / iStock
Honey bees (Apis mellifera) – like the wild bee species – belong to the family of true bees (Apidae). They are almost never interested in human food. After stinging a person, they leave their stinger behind in the skin, which is fatal for the bee. Most of the venom is dispensed in the first 20 seconds. Bee stings predominantly occur in spring and summer, whereas wasps are active in late summer and autumn. Wasps and hornets do not lose their stingers and can sting multiple times.
Asian hornet. Photo: Sergio Yoneda / iStock
Special cases have been observed in France, where the species arrived in 2004. Poison centres in France reported instances of eye irritation linked to the Asian hornet even though the hornet had not stung these people. Apparently, if threatened, the hornet can spray an irritating liquid in the direction of your eyes. 29 cases were recorded in France before 2020 – mostly people who came into contact with the hornets as part of their job (fire brigade or pest control). The symptoms ranged from temporary irritation that was quick to diminish to corneal inflammation to neuropathic pain. There were no reported allergic reactions among these cases (Link to the article).
In Switzerland, Tox Info Suisse has not yet recorded any confirmed stings from the Asian hornet or confirmed cases with the described symptoms. We do not expect any increased risk for the Swiss population. However, we recommend specialists in direct contact with a hornets nest wear well-fitting eye protection.
If you discover an Asian hornets’ nest, do not remove it yourself. Advise the cantonal specialist unit and call in a specialist. Report a sighting to the Swiss reporting platform (link to the reporting platform).