CURIOUSCITY
When wasps attack
Louise Cole opened her garage and wondered what the heck was going on. ‘‘I noticed wasps in the garage and I thought, well, that’s odd, they can’t be coming in and out from outside.
‘‘But I didn’t know what wasp nests looked like, so it wasn’t till I rang [Pest Proof] and said, ‘Look I can see wasps’.
‘‘But in the meantime, after I’d rung them, I thought – because I was cleaning out the garage – I’ll clean the attic instead. And then I saw them up in the attic.’’
While most nests are underground, these ones clung to the walls like grey balls of papier mache. The grey indicated the presence of German wasps. Common wasps make red nests.
Warmer weather – even this summer – sees the invasive pests out searching for protein, and native bush like the stuff surrounding Cole’s Lower Hutt home up Belmont hill is a perfect source.
Fruit and meat can also attract wasps further into your home.
Pest Proof general manager Jake Burns said nests the size of tennis balls could sometimes be killed with fly spray.
The best way to tackle bigger ones – he saw one in a house last summer that was the size of a chest freezer – was with insecticide powder such as Dust2Dust, which can be bought from hardware shops for about $20 per bottle.
Burns, in full protective gear, jabbed a nozzle into Cole’s attic nest and blasted its belly.
If you don’t want to call in an expert, his advice was to wait for the evening before a sunny day, because you do not want rain to discourage wasps from foraging the next day or washing away the toxin.
Cover yourself up – don’t forget your hands and face – and watch to see where the wasps enter the nest.
Shake the bottle, aim into the entrances, and spray 40g to 250g of powder, depending on the size of the nest.
When the toxin becomes active the next day, the wasps will carry it on them and blow it around. This kills the workers, queens, and their larvae.
In Cole’s attic, entomology expert Davide Santoro collected the live nest from the garage and took it back to Victoria University to be studied.
The university has a research team that is focused on four key methods of pest control, including targeting sex pheromones to prevent wasps from mating.
Another approach to make wasps impotent includes exploiting genetic mutations already present within wasp populations.
Wasps are a menace not just to homeowners, but to the New Zealand economy.
They threaten the winegrowing industry and forestry workers, and eat insects and honeydew that are important food sources for many native species, including kaka, tui and gecko. The damage costs the economy millions of dollars a year.