What's this bug????

[Rekky]

Hi All
Can anyone help me? I'm only growing veg in containers in my garden so this is my first year - I've got a little polythene greenhouse that some items are growing in, and one of my pots of carrots are covered in tiny white/yellow things. I thought it could be carrot fly but apparently you don't see them as they only attack the root? Could it just be white/green fly and how can I get rid of them or is my pot doomed? Worried as don't want them to contaminate everything else in my little growing house!! any help appreciated!!:

[Two_Sheds]

whitefly are white, and greenfly are green.
How yellow are your bugs? I don't know anything that is yellow.

btw. Carrots should be outside, not in a greenhouse.