While the hot weather in Switzerland offers a great opportunity for a picnic outside or a swim in a lake or river, it can also attract some unwanted visitors. According to experts, the continuous heatwaves seen in Switzerland in recent months, coupled with the end of the hay harvesting season, have led to a large invasion of hungry wasps.

Heatwaves in Switzerland force wasps to interact with humans

Over the last few months, Swiss cities and cantons have been gripped by continuous heatwaves, causing drought in several areas. The lack of rainfall has also led to a drop in the insect population, which has brought humans into conflict with some unwanted flying guests.

According to entomologist Christian Schweizer, “Due to the hot, dry days and the end of the hay harvesting season, the wasps are not finding much food.” Their traditional diet of aphids and caterpillars is hard to find during heatwaves, forcing wasps to find food elsewhere.

Most of the time, this means the creatures have to congregate around people to search for their next meal, increasing the chance of a wasp sting. “That's why they swirl around us and our plate in a very invasive way,” Schweizer explained.

People with venom allergies told to keep medicine with them

According to the Swiss Allergy Centre (aha!), 3,5 percent of the Swiss population are allergic to wasp stings. Allergy expert Roxane Guillod noted that three to four people in Switzerland die every year from life-threatening allergic shocks caused by wasp venom.

In a statement made on Wednesday, the centre said that as the encounters with wasps increase, all people with venom allergies should start carrying emergency medicine - typically antihistamines and cortisone - on their person when going outside.

If you get bitten and do have an allergic reaction, aha! recommended calling an emergency doctor on 144 in Switzerland and on 112 in Europe. The centre also advised sucking on an ice cube before help arrives, to delay possible swelling in the respiratory tract.

Too early to tell with wasp numbers in Switzerland will remain high

Currently, Switzerland is at the beginning of the wasp season, with their numbers expected to rise again in August and September. Schweizer said that it is still too early to tell whether the coming months will also be dominated by hungry wasps as “their numbers strongly depend on the weather.”