Plot Notes

A personal journal, open for the world to read, recording the progress of a novice allotmenteer on his allotment.



Weed it and reap.

Thursday, 1 July 2010

White-fly

Talk on the allotments tonight was of white-fly pests sucking the life out of cabbages and sprouts. So far my brassicas do not appear to have been attacked but several of my neighbours have suffered something of a brassica massacre. I have taken the precaution of consulting Oracle Titchmarsh. Helpfully, he suggests controlling whitefly biologically with the use of a chalcid wasp.

I quite like the idea of having a pet killer wasp which I can perhaps keep in a little box in the greenhouse and let it out a couple of times each day to dine on whitefly. I don't know how I would get it back in the box. Maybe I could train it with sheepdog trial style commands such as "come by" and "get down Shep".

I have searched for Chalcid wasps on ebay. The only ones I can find appear to be pre-historic specimens which have been entombed in amber for thousands of years. A few of these placed at strategic points around the plot may be sufficient to deter the white-fly, but I doubt it.

7 comments:

  1. Have to admit, I've never heard of chalcid wasps. only encarsia, a biological control for use in greenhouses. Bacillus thuringensis is the usual recommendation for cabbages etc., but I think that's for caterpillars. At work I alternate spraying with Savona and dusting with Derris. Both rely on contact so need to be thoroughly applied. Old boys reckon spraying with milk does the trick. Guess that works like Savona, the fattty acids blocking the whitefly larvae's breathing holes, or maybe the smell disguises the cabbage.

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  2. Wiz, Thanks for the Advice. It sounds like a trip to the garden centre will be called for this weekend to stock up on Savona and Derris. I'll leave the one man and his wasp routine for another time.

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  3. As I understand it, Derris powder is now longer available. I've used a spray containing Pyrethrins. It's natural (not that I care, I'd use napalm if it worked), but I use it beacause you can eat the stuff that's been sprayed after 24 hours. It's good for a few weeks.

    Doesn't the fairy liquid thing for backfly work with whitefly?

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  4. You are correct IG. According to allotment.org Derris powder has been taken off the market.I picked up some pyrethrins multi purpose bug killer in Wilkinsons today, on offer at £1.48 for 1 litre.

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  5. Sorry about that Phil, I'm still using stuff I've had for years. Wonder why it's been banned?

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  6. When you have finished with your trained killer wasp can I borrow him? :-)

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  7. Hi Phil, milk is the way to go, I did a post on it a while ago if you want to check it out. The cream off the top of a pint of gold top will do the trick, the fatty acids dissolving any soft-bodied critter, I like the thought of whitefly and aphids dissolving away! As Is says Bacillus is the thing for caterpillars although I enjoy squashing them by hand but obviously a bit time consuming.

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