Not if you cover it with a fine mesh net!
I've started cropping the carrots from the carrot temple:
Thank goodness I netted them. There's no carrot root fly on any of the varieties. And thank goodness I bothered to label the rows:
Not So Early Nantes would be a true description. The trouble is that once you have a net in place there is a natural reluctance to remove it so weeding and thinning can be overlooked for rather too long. Here's the net with parsnips beside and Runner Beans and Sweetcorn beyond.
Encouraged by the results I've even got a second net of (very) late sown carrots; Quick growing Paris Market.
I've weeded and thinned since taking this picture, but they have got some way to go before producing an edible crop. I've got plenty to keep us going even if they don't come good in time.
The nets aren't so pretty, but when the light catches them at a certain angle...
"Medication Time!"