Carrot fly

[Vince G]

It's that time of year again.

I've erected my "carrot shield". (Basically some leftover polythene from building my polytunnel, nailed to some wooden stakes, buried about 6 inches down and standing about 3 feet high around the carrots).

It's in its second year and looking a bit holey but the strong winds we've had here have ripped it apart.

So I've found some smart "pop-up" mesh cloches on fleaBay. The mesh is 4mm gauge. Obviously a solid shield like I had before is best, but will 4mm gauge be sufficiently tight to keep the carrot flies out?

[WendyC]

Just looked up enviromesh mesh size and it's 1.35mm. This is what I amongst many other people use to keep out the dreaded fly. I think you are right that 4mm is too coarse.

[rustylady]

Fact sheet here about carrot fly - apparently the adults are about 8 mm long, no idea how wide though Factsheet about Carrot fly

[Two_Sheds]

4mm isn't small enough a hole, sorry. They are the size of a normal housefly, and you can imagine a determined one wriggling its way through a hole that size: butterflies can get through debris netting, and mice can get through a pencil-sized hole.
They all breathe in, and squ-eee---eeeze

[Alison]

Vertical barriers don't work properly anyway (was rather disappointed that Monty was peddling this myth last week ), the only way I've found to avoid them is to cover the entire bed in enviromesh from sowing to cropping. When I uncover to weed I try to remember to spray some garlicy water around the place to cover up the smell and confuse the little ***s

[Bren In Pots]

I read on Garden organics site to mulch with grass cuttings because that goes towards preventing the females from laying their eggs.

Factsheet about Carrot fly