[NASH]

or does the fly lay all year ?

[Benandbill]

Never thought of netting against carrot fly.  I heard that growing them in a barrel is a good preventative method against the fly as they can't fly higher than 18" or so.  Also, growing them between rows of French Marigolds or onions is supposed to work as the fly are repelled by the scent.

I don't know how true any of the above is, some people will tell you it's nonsence.  I've heard the barrel thing a few times though and seen it practiced to good effect on our site.

Sorry I can't answer your question about whether the fly lays all year.  You'll need to ask a gardener 

[DD.]

Per thecarrotmuseum.co.uk

"There are usually two, sometimes three, generations of carrot fly in a year. The first and worst attack occurs mid-May and mid-June; subsequent attacks are in Autumn and in Winter in mild seasons. "

Pretty much covers all year, then!

[NASH]

On it stays then DD !

[DD.]

Subject to the forecast wind, mines still on!

[sunshineband]

Subject to the forecast wind, mines still on!

and in the face of that advice --- so will mine be