MickSturbs said:



Hello,

I have black fly munching my runner beans, I've used an organic spray
which seemed to work immediately after the spraying (couple of days
perhaps) although the little vermin reappear shortly afterwards.

You will need to spray at least three times, at three day intervals to
gain control of the black bean aphid (Aphis fabae). The organic
spray you used (most probably) has no residual effect.

The plants are doing well, plenty of flowers and a few beans coming
through now. As there is lot foliage, I'm finding it difficult to reach
the entire underside of the leaves with the small spray I've been using.
It's also very expensive.

I am a complete novice; this is the first year I have grown. It seems my
father's green fingered genes have taken a while to kick in for me. I
would be very grateful of any tips members could give me, names of
insecticides, method of spraying etc.

You might want to invest in a small pump sprayer and some insecticidal
soap concentrate.

Don't use soap spray in the heat of the day; while insecticidal soaps
are formulated for use on plants, they can still sometimes damage the
foliage. Spray in early morning or in the evening. It may even be
best to come back later and rinse the plants with plain water. (The
soap spray acts on contact and will kill the aphids very quickly but
will have no residual effect on the insects, so rinsing it off later won't
help the pests, but can protect the plants from any possible harm.)

http://www.which.co.uk/documents/pdf...fly-151473.pdf
--
Pat in Plymouth MI

"Vegetables are like bombs packed tight with all kinds of important
nutrients..." --Largo Potter, Valkyria Chronicles

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