Chillies Under Attack

I was watering my Dorset Nagas when I noticed they are under attack. These little creatures are tiny and very well camouflaged ; they don't appear to have been doing much damage but not sure they are doing them any good either. Going to purchase some insecticide tomorrow - unless anyone has any other suggestions or can assure me they are good for the plants?

The plants are looking good - currently standing 2.5' tall and just about to flower. Hopefully going to get some really hot fruit from them!