? root aphids! help!

[crazii_c]

ive just discovered what looks like root aphids on my lettuces. my lettuces hadnt seemed to increase in size at all over the last few weeks, which was strange. when i just pulled one up i discovered loads of tiny white/grey liitle insects covering the roots. also parts of the soil looked bluey white around where the roots had been. no wonder they had been stunted! after a google it seems to match best to the root aphids:
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my question is how do i get rid of the little buggers? any sprays? nematodes?

my lettuces are grown in a small patch of soil in my back garden. will they spread to all my other crops in the patch of soil, or do they just target lettuces?

[rustylady]

Opinions vary - the Harrod site says use normal insecticides (I would think soak the root area) HarrodHorticultural: Aphid Control but another site doesn't hold out much hope once you've got them http://www.which.co.uk/documents/pdf...ids-153697.pdf