Have you noticed the busy activity of wasps in the garden in late summer and autumn? Many of these are harmless and beneficial native wasps, like flower wasps. These perform an important role as pollinators and as biological pest control on the farm or in the garden. Some help control caterpillars which they feed to their larvae. Others lay their eggs in or on a range of host insects. The larvae hatch and eventually kill the host. There are wasps which parasitise leaf-eating scarab insects, pasture grubs and Christmas beetles and whitefly pests of tomatoes and cucumbers. So it’s worth loving your wasps.
Landholders and the Koori Work Crew here in the Bega Valley have recently reported seeing (and feeling the stings of) a less loveable wasp – the European wasp (Vespula germanica). This wasp is neither harmless nor beneficial. It poses a threat to local ecosystems, personal safety, recreational values and rural industries on the far south coast.
European wasp stings are painful and, unlike bees, a wasp can sting people repeatedly. While European wasps generally won’t attack unless provoked, the nests (most commonly in the ground) are often hard to see and people can inadvertently step on or disturb them and be set upon by numerous wasps. This is potentially lethal for those with wasp allergies. Wasps may also enter soft drink bottles in search of sugar which creates a risk of being stung in the mouth or throat.
Environmentally European wasps pose a significant risk to ecosystems as the wasps prey on indigenous fauna (particularly other insects) and compete for nectar. This reduces food for native birds, reptiles and animals and impacts on species that pollinate plants. European wasps are responsible for large biodiversity losses in New Zealand, can threaten rural industries such as fruit growing (particularly grapes) and bee keeping and can adversely impact on tourism by invading picnic areas and outdoor food venues.
Native to parts of Europe, Asia and North Africa, the European wasp and doesn’t have natural predators in Australia to keep its numbers in check. In Europe, the cold winters ensure that only the Queen wasp can live, but the warmer climate of Australia means the entire nest can survive and can reach dangerously large proportions, up to 100 times larger than the nests in Europe.
How to know if you have European wasps
Have a look at this handy identification guide from the WA Department of Agriculture which will help distinguish between European wasps and other look-alikes. European wasps are often confused with the widespread yellow paper wasps (Polistes dominulus) which are beneficial and less aggresive but which will still sting if their nests are disturbed or threatened.
If you can safely take a photo of your wasp, upload it to the Atlas of Life in the Coastal Wilderness. It’s easy to do and an expert moderator will identify your sighting. This will start to build a better picture of where European wasps are occurring across the Bega Valley. You can also let Andrew Morrison from Bega Valley Shire Council know by emailing firstname.lastname@example.org
How to control European wasps
Try and locate the nest site (this Victorian government website provides photos and details on how to do this). The safest approach to controlling European wasps is to engage a local pest control contractor to destroy the nest.
What to do if you’re stung
Although they are painful (usually far more painfull than a bee sting), isolated wasp stings seldom cause serious problems. The initial sensations of a wasp sting can include sharp pain or burning at the sting site followed by a raised welt around the perimeter and usually the pain and swelling recedes within a few hours of being stung. Use a cold pack to reduce swelling and pain, use pain-relieving medication and creams and be alert for signs of anaphylaxis, a life-threatening reaction that can result in death from swollen airways.
European wasp venom contains toxins that can cause allergic reactions in susceptible people. Around one in 10 people who are stung two or more times become allergic, which means they will experience severe reactions to any subsequent stings.
When to call an ambulance
The most severe allergic reaction of all is anaphylaxis, which may be life threatening. For any life threatening symptoms such as anaphylactic shock immediately phone 000 to call an ambulance. For more details on first aid and when to call an ambulance visit the Victoria state government website on European wasps.