The Cottage Smallholder

Unbelievable I have just noticed that some of my overwintered (in the conservatory) salad leaves are covered in pests (aphids?). On the top of the leaves is something which is dark colored and has wings while underneath the leaves is what appears to be wingless and green and much smaller pest. No damage as yet to the plants themselves no sticky type substances or discolored leaves etc. As I am about start planting seeds for tomatoes and sweet peppers I need to get them wiped out quick. I should say that I am not positive about what they are......other than an extreme nuisance. I am happy to loose all my trays of salad leaves (well happy might not be the right word) even though I am looking at 15 trays (there goes my salad self sufficiency). So any pest control product would do the more potent the better! just looked again some of the winged type appear to be green and on top of the leaves and some of what appear to be wingless are possibly brown. I have moved the worst affected trays outside in the cold so some may have buggered off. Magnifying glass definatly shows some green winged flies.  HELP