What has mangled my onions?

[dilettante]

I've noticed over the past month or so my onions' leaves have been curling up and twisting and generally getting very distorted. A cursory googling suggested thrips but I found none on there. It occurred to me today to dig one up and check out the bulb, and I took some pictures.




In the last picture if you look closely you can see a little orange/brown thing, which I think is some sort of pupae. Interestingly, the actual bulb looked fine, aside from having this thing inside it. It didn't appear eaten, the roots looked ok, it's just the leaves that have become distored.

Now, assuming there is a little grub, or pupae, or whatever it is, in every onion with twisted leaves, are they all buggered? It seemed to be spreading, for a few weeks. Fortunately I've planted far too many onions anyway. Of my three onion beds, one is next to the already infected one, and the other is half way up the plot. I've got loads of shallots to plant out still, and I'm really looking forward to eating them, so I'd like to prevent them getting attacked.

Thoughts?

[Greenleaves]

It could be onion fly.....in one of the pictures it looks like the ground has manure on it.....if it is manure is it from a safe source

[dilettante]

It could be onion fly.....in one of the pictures it looks like the ground has manure on it.....if it is manure is it from a safe source

I did think onion fly, but I looked in Dr Hessayon and it says the bulbs would be tunnelled, and the leaves drooping and yellow, which doesn't seem quite right. I do think I might have to burn the plants though.

It's not manure, it's Verve peat free compost. Would that still be a potential source of infection?

[Greenleaves]

Unlikely, as you suggest thrips is the most likely culprit

[Jungle Jane]

The onion fly overwinters & emerges in May/June lays eggs & it's the maggots that do the tunneling damage,sticky traps are suggested to catch the flys & to burn affected plants. How do people get rid of the fly pupae,is it worth digging up the good onions otherwise they're at risk or leave them to hatch out & enclose the area with a tunnel cloche or something & use sticky traps? It's good you noticed now!
BBC - Gardening - Advice: Pest and disease identifier

[Scarlet]

I think it's alium leaf miner. You need to use enviromesh to stop it...though to late for your crop now.

https://www.rhs.org.uk/advice/profile?PID=643
I would ensure you cover all of the onion family in future. It's usually worse in the Autumn

[Mr Bones]

Definitely allium leaf miner. Sadly, affected onions rot, stop growing or take on an unpleasant gassy flavour.
I know how gutted you must be feeling, we were first hit a couple of years ago, there's a piccy on here somewhere Allotment 37

[Scarlet]

I didn't think it got as far up as you yet Mr Bones the allotment closest to me have had it for several years running. I covered all my garlic last year - to find that I had white onion rot instead!!!
How do you control it with you. Enviromesh?

[SusieG]

Ooh, crikey - do I need to worry for my onions?
I have a bed planted out in April. They look fine, but they are not covered with mesh and now wonder if they should be covered?

At the end of this bed I have some garlic planted too ...

[Mr Bones]

I didn't think it got as far up as you yet Mr Bones the allotment closest to me have had it for several years running. I covered all my garlic last year - to find that I had white onion rot instead!!!
How do you control it with you. Enviromesh?

We cover with Wondermesh, it's like enviromesh but has tighter 0.6mm mesh.
Re white rot, since taking the advice of an older gardener of dipping onion sets in malt vinegar prior to planting we now lose hardly any to it. I don't know why it works but before we'd lose maybe 40% now it's just an odd couple of bulbs.

[dilettante]

Well bugger. That is a right bloody pain in the back side. Annoying as it is, at least onions are cheap to buy. I would/will be more annoyed if/when a higher value crop is ruined.My garlic seem to be OK though, and they're planted in the two affected onion beds.

[Scarlet]

Have you had a good look? I know one of the boys on the allotment grows his garlic in a GH now because of the leaf miner.
Agree , pain in the backside

[dilettante]

No, admittedly I haven't looked. I didn't bother because they've remeained perfectly straight standing and look fine. I will tomorrow.

[dilettante]

Welp, that's all my onions and almost all my garlic done for. The second bed has some twisty leaves, and after digging some up, although I didn't find the pupae, I did find some rotten bulbs. Very slimey. those were the first thing I planted, I'm so annoyed to be so close to the harvest and have them ruined. Grr. Live and learn though. Clearly need to invest in plenty of protection for all my precious crops. I was a bit put off by cost, but actually the time lost to ruined crops, more than the money, is just not worth the risk.

[SusieG]

dilettante, that's really bad luck ...
As you say, especially when it's so close to their harvest time ...
I'm keeping a very keen eye on my onions/garlic now ... What were the first signs you noticed? But suppose it's probably to late to do anything then though ...?