PARTS of Mundaring and Kalamunda have become hotspots for European wasp activity with 45 nests found in the two local government areas this season.
Department of Primary Industries and Regional Development senior technical officer Marc Widmer said more than 124 colonies of European wasps have been eliminated so far this season compared with 52 the previous season.
Mr Widmer said it was the highest number of European wasp nests found in one season.
“We still need more help from the public to locate as many nests as possible especially in this year’s hotspots which include Greenmount and surrounding suburbs (32 nests), Lesmurdie (13 nests) and Orange Grove-Kenwick-Maddington areas (39 nests).”
The nests have been destroyed across an area almost the size of Tasmania.
A network of more than 2000 traps was deployed by the Department of Primary Industries and Regional Development (DPIRD), local governments and community members as part of this year’s campaign which ends in June.
Every year, fertilised European wasp queens are accidentally transported into Western Australia in freight and cargo from the eastern states.
Mr Widmer said it was difficult to determine the exact cause of fluctuations in numbers from season to season.
“It was a bad year for wasps last year in the east, so this translates to a higher likelihood of wasps being transported into WA.
“We’ve had a fantastic response from the community in reporting European wasps, which we believe has contributed to the higher number of detections this year.
“DPIRD has not found evidence of overwintering nests this season, but it’s possible a couple of nests have gone undetected last year leading to an increased number this year.
“This highlights the need for quick reporting and early detection and it’s critical that we locate and remove as many nests as possible before winter.’’
Mr Widmer said the wasps must be eradicated if the state was to remain free of the pest, which was considered one of the worst wasps in the world – harmful to people, outdoor lifestyles and horticultural and agricultural industries.
This season one nest was found in a hollow paperbark but the nests are usually below ground with the entrance showing as a hole in the ground – on rare occasions they are found in a roof or wall cavity.
During the summer months the nests can grow to be the size of a basketball or bigger.
The nests are round or football shaped with an outer covering of insulating material similar to grey paper mache or egg carton material.
Once a European wasp nest has been identified it needs to be treated and removed free of charge by the Agriculture and Food section at DPIRD.
All nests (dead or alive) must be reported.
People are advised to not attempt to treat a nest themselves and to not approach a nest as wasps can sting repeatedly.
Paper wasps, which can be confused with European wasps, feed on insects including caterpillars, flies, beetle larvae and nectar.
They are not scavengers and will not target barbecues, meat products, pet food or dead insects.
What to look for…
EUROPEAN wasps are scavengers, so if a wasp settles on pet food, fish or other meat products, including dead insects, they should be immediately reported to the department.
They are the same size and shape as a bee, but with yellow legs and are a bright yellow and black with black antennae.
Body marks are similar to yellow paper wasps.
Photos can be supplied using the department’s MyPestGuide Reporter app or webpage mypestguide.agric.wa.gov.au
The app can be downloaded free from Google Play or the App Store.
Alternatively, contact the department’s pest and disease information service on email firstname.lastname@example.org or phone 9368 3080.
To adopt your own surveillance trap or for more information on European wasps, visit the department’s website at agric.wa.gov.au
Trapping is as simple as hanging a trap in a tree, inspecting the trap and changing the raw fish lure every fortnight (weekly is even better).
By Anita McInnes