Monday 9 July 2012

To kill Green fly or not?

Greenfly colony on broad bean tips
Summer is great but its also when all your main pests arrive. Very often advise dispensed by learnered scholars in books about what to do with an invading pest army arrive goes against your own good common sense and better judgement. And because we are conditioned to believe "experts" and not trust our guts we often do things we would rather not do.

I had just put down Amateur Gardening and was reading Anne's column about aphids on broad beans when  I noticed clusters of greenfly (not the usual black bean aphid) on the growing tips of all the broad beans. The typical advise is to pick off the tips and dump them, taking the munching horde of invaders with you. But after breaking off the first few tips I found myself face to face with a fat contented ladybird and realised she was already hard at work destroying the new greenfly colonies. On the other side of the bed I found hover flies darting in and out of the broad beans grabbing greenfly for a lunch on the go!

Does it make sense does to go out spraying even harmless soap based mixtures on pests, or breaking off the growing tips, when you can allow a natural food chain to work on your behalf ?
Aphids are the Junkies (and sluts! they reproduce at savage speed) of the insect world-they carry around diseases from plant to plant. Chocolate spot, the black death of broad beans, is often transmitted by them. That's the real fear behind getting aphids on broad beans, not that they are sucking sap out of the plant but that they are spreading an incurable disease while they are at it.

Fear has the world gone mad, I think I'll just take my chances. These are mature plants with really good pods filling with beans.I left my ladybirds and hover flies to it and I will keep an eye on things to see how it goes. By the way Anne's advise on the topic was very good;

1 If the beans have set pods and you have ladybirds taking care of the problem don't worry about it too much, keep an eye on it, but natural predators should sort the problem out.

2 If the plants are just flowering do control the problem as aphids can infect and distort the flowers and later pods.

Amen sister.

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