Onion Fly Damage

[Tig]

This happened to me last year!

At least I know what I am dealing with now, so thought I would share.

These may look like three good tennis ball sized onions ...



But on closer inspection there are signs of damage around the stems, little cracks in the skin ... these are the culprits -



Onion fly maggots

And when you peel off the outer layers you find some have moved on a stage to pupae ...



And by the time you have finished cutting out the damage you have golf ball sized onions (if you catch them quick enough, otherwise you end up with nothing!!) ..



All my onions have been lifted now, cleaned and blanched, these horrible insects also attack leeks and garlic! I just hope they ain't been at my garlic

x Tig

[Rosefriend]

That is horrible Tig - sorry.

I have decided that I shall buy my onion plants in the future - they seem to be far better than the seeds which did nothing and the sets last autumn are not very good at all. The ones from this year are looking great though and up to now without Onion Fly....however after seeing that little lot I shall have a good look tomorrow morning.

Thanks for the warning Tig.

RF

[Tig]

I do wonder if I should give up trying to grow them RF - even leeks were ravaged last year. The Japanese onions were not as badly affected because they are in all winter and the pests have less time to attack them. I should cover them with fleece really, but as I have mixed veg plots rather than dedicated ones it is a tad impractical

x Tig

[Rosefriend]

After having a good look all mine seem to be OK but I have some yellowing leaves on the onion plants that I bought. There were 3 - 6 seeds growing in each module so I am going to take some off and eat as spring onions to give the others a better chance.

The only think would be netting Tig I think - and as soon as they are planted - bit of a pain really.

RF

[Ladygardener]

Gosh thanks for starting this thread Tig. I had no idea about the onion fly damage. I won't have time today or tomorrow as Ruth is on her way to me from the airport but i'll have a good look on saturday. I might even lift some of my onions, they were sets planted end of feb as were the shallots. I've written somewhere else that the leaves have been yellow and starting to rot but I did'nt know what to do.

[carolann]

Touch wood I have not seen anything like them on my Onions, they are still only golfball size yet, but thanks for showing us what they look like and the signs to look out for.

[Chuckles]

hell Tig they are awful

[farmersboy]

A couple of things that may help in this,dont grow onions/leeks on freshly manured ground,manure attracts the flies,
And thinning causes an onion smell,which also attracts the flies,so growing from sets,which dont need thinning,onion fly is less likely
Also keep hoeing round the plants

[Ladygardener]

I've lost most of my onions and shallots this year. They were grown in a new bed and may have attracted the onion fly because of this. Most of them ended up squashy and yuckky to use the technical term. Next year they'll have to be grown in containers.