[RJR_38]

So it looks like for the second year in a row my onions will be ruined by this bug - I also found a few in my garlic when I started harvesting!

Does netting them work (debris netting) or will they already be in the ground for next year does anyone know? Can't believe that I am going to have to net another whole family of crops

[mumofstig]

It's enviromesh/veggiemesh you need to use, and yes, only net where there were no onions the year before, or they may already be in the soil.

[Flowertot]

I know how you feel  . I have repeatedly lost all my onions, shallots and garlic to them or onion fly. This year is my last ditch attempt to get a decent crop. I am growing onions and shallots under an enviromesh cage in a bed next to last year's bed (across a 45cm paving slab path). I have not yet looked very closely at them to see if any are affected (I am nervous to open up the cage more than absolutely necessary in case some nasties get in) but from my limited peeking they appear to be in much better shape (taller, greener) than those on other plots. I plan to harvest a green onion or two sometime this week so I will let you know if they are ok. Fingers crossed. I also have my tray of leeks in that cage waiting to go out under enviromesh once I've harvested enough potatoes 

[Flowertot]

Ok this evening I pulled up one cluster (I wonder what the right word is  ) of shallots. The leaves are still green but the bulbs are huge...and there are no signs of maggots! Hooray  I am well chuffed. I will check an onion next time but things are looking promising. Enviromesh is not cheap but hopefully if it lasts for a few years it will be worth the expense for the sake of being able to grow onions etc.

[RJR_38]

I have lots of debris netting which I use for brassicas successfully with  the cabbage whites. Is this no good for lead miner then?

[mumofstig]

The fly is only 3mm long, so much smaller than cabbage whites, most sites say enviromesh or fleece.

http://www.wlaf.btck.co.uk/PeskyPests/AlliumLeafMiner