White Fly on Brasicas

[Benjamin]

Our sprouts and purple sprouting are covered with tiny white flies. We've been spraying for about a week now with an Insecticide Polyvalent which we used to get rid of black fly on nastertiums earlier this summer but without any diminishing effect.

The container says for Multi-Insectes ( pucerons,acariens, chenilles et vers ).

Any suggestions anyone?

Benjamin

[chris pp]

I'm a little surprised that you think it's a problem on those two plants, shouldn't have any effect on the bits that you are going to eat, white fly should be long gone before they are ready.

Still, only my view.

Chris

[Meg]

Apparently whitefly are resistant to most pesticides.

Is it really worth all the effort of spraying them so regularly?? I'd either not grow brassicas again or try some organic methods.

Also spraying with chemicals will prevent natural predators.

Louise

[Benjamin]

Thanks for both of your replies. Never knew that white flies are harmless and don't do any permanent damage.

We are new to vegetable gardening so the information is absorbed and stored.

We live in a rural location and we've hardly seen a ladybird all year long, even before we sprayed the nastertiums.

Benjamin

[Meg]

One natural predator of white fly is the parasitic wasp Encarsia formosa.

You can actually buy the pupae online! Also i have seen ladybird larvae available as well.

I also didn't see many ladybirds, until about mid July.

Apparently poppies and marigolds planted in the veggie patch attracts beneficial insects,

like ladybirds and hover flies. I will give it a go next year. It's all a bit trial and error for me this year!

Happy gardening, Benjamin

[Benjamin]

We've got a few flowers around the veg patch with a large budlea (sp?) right on the edge but without any problems from cabbage whites ( which we'd put up with because we get so much enjoyment from seeing all the butterflies).

We've got lots of marigolds at the front of the house about 30 metres from the veg patch but again no sign of ladybirds.

Benjamin

[chris pp]

The only way to have a healthy population of ladybirds is if there is sufficient food for their larvae to eat, therefore you need aphids to be present for some years somewhere in your garden.

Now there's a catch 22 for you!

Try to have a wild area where the aphids can munch away on some species of plant that don't matter too much to you, they won't kill them. Thistles are good.

Chris