Reports of European wasp nests are on the increase in the Bega Valley. Recently, four nests of this potentially deadly pest have been reported to Local Land Services or Bega Valley Shire Council (BVSC) staff. These reports are partly due to the time of year, as the nests are at their most active in late summer and autumn, but may also indicate an increase in the population of this pest in the region.
The European wasp is a bee sized wasp with bright yellow and black markings and yellow legs(see photo). Queen wasps build an underground nest (occasionally in roof cavities or tree stumps) which is maintained and protected by numerous worker wasps. Nests can be identified by the constant stream of wasps coming and going from the nest, often just a small hole in the ground. Individual wasps are often seen around rubbish bins, picnic areas, fish cleaning tables and the front of cars (searching for squashed insects).
The European wasp (Vespula germanica) is often confused with the European Paper Wasp (Polistes dominulus), but there are some significant differences between the species: (a) The European Paper Wasp has a more slender body and longer hind legs which trail behind it in flight; (b) European Paper Wasps fly fairly slowly and hover while European Wasps fly swiftly; (c) European Wasps have all black antennae while European Paper Wasps have orange antennae with black base; (d) European Paper Wasps build a paper nest, usually hanging downwards with open cells on the bottom. The nests are often built under eaves or in outbuildings.
Europe vs Australia and New Zealand
In its home Europe this wasp has numerous predators and parasites and nests are killed off during the cold winters. In Australia and NZ the wasps are free of their natural controls and the relatively mild winters (particularly here on the south coast) allow some nests to survive for several years. These nests can reach dangerously large proportions, up to 100 times larger than the nests in Europe.
The regional situation
In the ACT European wasps have become a considerable problem since they were first detected in the mid 1980’s. Originally an issue in the suburbs and central Canberra, the wasps have spread into rural and bush areas, impacting on vineyards and forcing the closure of some picnic areas due to their high numbers and the risk of serious injury to visitors. Low numbers of European wasps have been present on the south coast for several years but they have the potential to build into a serious problem.
Issues caused by European wasps
European wasps pose a threat to local ecosystems, personal safety, recreational values and rural industries on the 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 are often hard to see and people can inadvertently step on or disturb them and be set upon buy numerous wasps. This is potentially lethal in the case of children or those with wasp allergies (1 person in ten is likely to be allergic to the proteins in wasp venom). 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. European wasps can threaten rural industries such as fruit growing (particularly grapes) and bee keeping and can adversely impact tourism by invading picnic areas.
What can we do?
BVSC is keen to determine the extent of the European wasp problem in the valley and any reports of nests can be made to Andrew Morrison on 6499 2253 or at firstname.lastname@example.org. BVSC advises that landholders contact a pest control professional to treat any nests that are found on their property and warns against attempts to treat the nest themselves as it may be home to many thousands of wasps which will be fiercely protective.