Department of Agriculture and Food senior technical officer Marc Widmer said European wasps were often confused with the common yellow paper wasp, as both were striped yellow and black.

“However, there are a number of characteristics that will help to tell the difference,” he said. “Most notably, paper wasps dangle their back legs in flight. European wasps have a stout body, more like a bee and hold their legs close to their body.

“Paper wasps are longer and thinner, and tend to hover. European wasps on the other hand fly quickly and purposefully.”

Another difference is that European wasps have black antennae, while paper wasps have orange-brown antennae.

European wasps are also attracted to meat products, including pet food, steaks or dead insects. Mr Widmer said any wasp attracted to meat was definitely suspicious.

“One of the main concerns is that European wasps are attracted to outdoor dining, be it alfresco, a barbecue or the school ground,” he said. “In particular, drink cans are a danger because if a wasp crawls inside, the person could be stung in the mouth or throat. Stings from a European wasp are very painful and may be life-threatening.”

Mr Widmer said fertilised queens arrive in freight from the eastern states, and the most common finds were in industrial areas, where major freight depots were located. However, queens can be transported anywhere.

So far this summer 17 nests have been found - one in Kalgoorlie and 16 in metropolitan Perth, including one in Bassendean, one in Osborne Park and 14 in the Kewdale and Welshpool areas.

Mr Widmer said Western Australia had been battling European wasps for 35 years. “Public reports of suspicious wasps are critical to locating and destroying any nests,” he said. “Local governments are also playing an important role, with some now taking part in the new ‘adopt-a-trap’ initiative.”

A Gardennote providing wasp descriptions can be found on the Department of Agriculture and Food website www.agric.wa.gov.a u

The public is urged to report any sightings to the Pest and Disease Information Service on freecall 1800 084 881