[mattwragg94]

Right ive got carrot fly - what i want to know is - can the affected carrots be composted?

[LilacSandy]

I would assume the little blighters will carry on their life cycle in the carrot and hatch when ready.  If they are near the top of the pile I presume they would just fly away to start breeding on your, or someone else's crop next year.

Just make sure you dig over your patch to expose any left in the ground and make sure you do not grow any carrots in the same ground next year.