The English-speaking section of natur & ëmwelt has published information on what to do if you come across a wasps' nest.

Wasps are not the most popular of insects – at least not among humans. They make a nuisance of themselves at outdoor mealtimes, and they tend to build their nests in inconvenient places – inconvenient, that is, for humans.

It’s this wasp/human interface that is clearly the problem. And the problem has recently come to a head because local fire brigades, which used to respond fairly readily to appeals to rid householders of their unwelcome lodgers, now intervene in only the most pressing of cases. From the conservation point of view, it is also a practical problem.
 


natur & ëmwelt cannot come out and deal with the problem itself – it can hardly be part of a nature protection NGO’s mandate to selectively exterminate animals. natur & ëmwelt’s conservation advisers are, however, happy to answer phone and e-mail enquiries, in English too. Basically, what they’ll tell you is:
 
• don’t try to get rid of a nest by yourself; it’s only authorised in serious cases, and is something that should be left to the professionals.
• try to find ways of living with wasps: it’s only for a short period, and the wasps mean no harm; they’re trying to get on with their lives just like you’re getting on with yours;
• what wasps need is a clear flightpath to their nests, so try to keep out of their way;
• if there are wasps around, be calm and don’t flap around; there are ways of keeping them off your food and drink (e.g. have only water on the table – it’s healthier anyway!); if they can find other food sources, they'll generally be less interested in your sugary drinks or the plum tart. Cultivating flowering plants (like lavender and thyme) in your garden will benefit the bees and the wasps, and will keep them away from the table. Or put a plate with some sliced fruit further away to give them an alternative – and a small amount of water so they don't get dehydrated;
• the smell of lemongrass can keep them away; so a scented candle at the table can help.
 
The gardener's friend: wasps are important pollinators and devourers of insects and larvae

Wasps have their part to play in the evolutionary scheme of things, though this may not be immediately evident (a bit like humans in that respect?). There are lots of different wasp species: over 500 in Luxembourg alone. But most of these are solitary wasps. It’s the species that form big colonies and build nests, often in or on buildings, that are the problem; and there are essentially three of these: the Common Wasp, the German or European Wasp, and the Hornet (the Hornet being just a big wasp, and ordinarily no more ‘aggressive’ than the other species).

Wasps feed mainly on plant nectar and juices, and on fallen fruit, though the young will be fed protein-rich insects, spiders and other fleshy material. At the height of summer, with many mouths to feed, a Hornet colony will get through some 500g of insects and larvae – about the same as five Great Tit or Blue Tit broods. So wasps are very definitely the gardener’s friend. It’s only late in the summer, with other food becoming scarce, that they can’t resist the temptation of the Schueberfouer and other such wasp-ridden events.
 
All but the queen wasps die off as winter approaches, at which point the nests (intricately made of paper produced by the worker wasps stripping off tiny slivers of woody material and chewing it into pulp) can be removed and either kept or disposed of.

A wasp’s sting is used to kill its insect or larva prey. Humans are not normally mistaken for insects. If you are unfortunate enough to get stung, it will, well, sting for a bit. Only very few people react allergically to wasp stings. It’s best not to get stung in the mouth, though...