Harmless lookalikes: wasp, hornet or fly?
By Wespenprofis.ch · Reviewed by:Fachbewilligung Schädlingsbekämpfung VFB-S · Updated: 3 July 2026
At a glance
Not every wasp-like insect is dangerous. The mammoth wasp, the giant woodwasp and the hoverfly resemble wasps or the Asian hornet, but none of them has a sting that works against humans. The reliable ways to tell them apart are the number of wings, the length of the antennae and the typical behaviour of each species.
Not every black-and-yellow or large, buzzing insect is a wasp. Over the course of evolution, several native species have adopted wasp-like warning colours without having an effective sting of their own. Once you know these lookalikes, there is no reason to be afraid of them.
Insects that are often mistaken for wasps
Mammoth wasp (Megascolia maculata): One of the largest wasps in Europe, black in colour with a yellow crown and four striking yellow spots on the abdomen. Because of its size it is regularly taken for the invasive Asian hornet, but it is a rare, heat-loving species in Switzerland and is not aggressive towards people.
Giant woodwasp (Urocerus gigas): Black and yellow, and impressively large at up to 40 mm. Females carry a long, thin ovipositor at the rear of the body that looks like an oversized sting, but it serves solely to lay eggs in softwood. It cannot be used to sting a human.
Hoverflies (e.g. Volucella zonaria): With their black-and-yellow markings, hoverflies mimic wasps convincingly — a strategy designed to deter predators. As flies, however, they have only one pair of wings instead of two, plus noticeably large eyes and short antennae. They have no sting whatsoever.
How to tell the difference reliably
The most dependable clue is the number of wings: true wasps and hornets have two pairs of wings, hoverflies only one. Flight behaviour also gives a lot away — hoverflies typically hang motionless in the air before darting abruptly to a new position, something true wasps never do. With large, sturdy insects it helps to compare the markings against the species profiles under /arten, for example the European hornet.
Why these species are harmless
Neither the mammoth wasp nor the giant woodwasp nor hoverflies defend a nest near your home — they live solitary lives or lay their eggs unnoticed in dead wood. Other furry, wasp-like insects such as the violet carpenter bee also look intimidating because of their size, but are exceptionally peaceable. With all of these species, control measures are neither necessary nor sensible. If you are unsure about an identification, feel free to send us a photo — and for a comprehensive overview of all native species, see our guide “Identifying Switzerland’s wasp species”.
Frequently asked questions
Is the giant woodwasp dangerous?
No. The long, thin projection at the rear of the body is an ovipositor used to lay eggs in dead wood, not a sting. The giant woodwasp cannot sting people with it and is completely harmless.
How do I tell a hoverfly from a wasp?
Hoverflies such as Volucella zonaria have only one pair of wings instead of two, strikingly large eyes and short antennae. They also have no sting at all, so they cannot sting you.
Is the mammoth wasp an Asian hornet?
No, even though its size means it is often taken for one. The mammoth wasp has a yellow crown and four yellow spots on its abdomen, and it is not aggressive towards people.