Tuesday, 27 January 2009

European wasps

Streuth! A gadget that really works!

All those lettuce seedlings require daily watering, and all of a sudden this small patch of moist soil was attracting European wasps (also called German wasps, Vesbula germanica) - a recent introduction to Australian and a declared pest species. They'd land on the seedlings, and head down into the soil from there, so I suspected a nest was forming in the cool shade - surely the most pleasant spot on the property amidst the current heat wave (41 Celcius, 106 Fahrenheit, three days in a row!)
These wasps are certainly common in Germany, and hang about food, especially when picnics are underway. I've never been stung, but swatting at them drives the Germans into a frenzy, if not the wasps, although the latter are supposed to be particularly aggressive (shout the Germans in a frenzy) to whoever happens to be holding the tea-towel that just flicked at them.
I had David and Gill Corkill over for tea last week; David and I were both editors of The Living Soil magazine at different times. So I dug out all the old SASA back-issues of the magazine (which had mysteriously been left in my care) and gave them back to David who, unlike me, is a life member of the Soil Association of South Australia.
There, among all that old stuff, were some fly-traps. I've only had them unopened in the original boxes for five years, such being my lack of faith in garden gadgets, but the flies around the compost bins have been building up in this heat, so I pulled out these plastic thingies to put them to use. All one has to do is to take the bait powder (which smells like dried fish meal) and mix it with 500mL of water in the bottom of the jar. The flies crawl in through the inverted cone, but can't find their way out, leading to death by drowning.
In the first half-hour of deployment, I'd caught one European wasp, so I moved the trap up to the lettuce seedlings where those wasps were really buzzing about.
Next morning, 25 wasps, none still airborne, but only one Australian blow fly.
There's a moral to this little story; if only I could figure out what it is?


chaiselongue said...

I almost feel I should apologise for our European wasps ... but I'm glad the trap worked! We've used a similar home-made method with jam jars.

Veggie Gnome said...

We've got one of those, too! They do work very well. But beware, after a few days they stink to high heaven!

Anonymous said...

Andrew thank for this and your other earlier story.. I've used permethrin powder on nests here on Biopark and not felt comfortable about it..Not permitted under organic standards normally but 'allowed' if required to deal with a pest like European wasps ( But it has to be declared to the certification body )

Bill Hankin

Anonymous said...

PS : Blow flies are not Australian either.. Thy are foreigners....They need sheep or cattle & their dung to breed in. Where there are dung beetles blow flies are scarce...

Bill Hankin

Anonymous said...

The European wasp queen sends out another worker to set up a new nest when she feels the workers are becoming extinct so it doesnt work as a deterrent to catch them and kill them. Poisoning or obliterating the nest is the only way to get rid of them.