Week 13: Onion Maggots (Hylemya antiqua!)

From humble beginnings as tiny little Seed Onions, they have enjoyed around ten weeks of growth on my plot. But as some followers will note, I have commented on their apparent strange behaviour for a few weeks now.

In just two weeks, my shallots are growing and settling in.

In just two weeks, my shallots are growing and settling in.

My Shallots and Stuttgarter Onions look really settled in their new bed.

My Shallots and Stuttgarter Onions look really settled in their new bed.

Onions and Shallots growing well with lots of leaf growth.

Onions and Shallots growing well with lots of leaf growth.

Main onion crop doing well although the garlic (late planted) has disappeared and is no showing signs of growth.

Main onion crop doing well although the garlic (late planted) has disappeared and is no showing signs of growth.

Onions looking odd and damaged. I have wandered the Allotment and some other plots have strange onions as well. I have put out slug pellets after finding lots of trails and slugs eating the onion leaves. Have to keep an eye on them.

Onions looking odd and damaged. I have wandered the Allotment and some other plots have strange onions as well. I have put out slug pellets after finding lots of trails and slugs eating the onion leaves. Have to keep an eye on them.

Closer up the Onions looks really damaged and ill.

Closer up the Onions looks really damaged and ill.

I consulted with other Allotment Holders who were able to tell me that I have Onion Maggots which is something no chemical treatment is available for domestic use. It was suggested that some of my onions may be alright to eat but I would need to carefully examine them to find signs of maggots as no spray would clear it away. I know I need to crop rotate my raised beds, and do not have full knowledge of what was planted there last year but disappointed that Onions will need to be grown under Micromesh or an equivalent to prevent the Onion Flies from coming onto my crops. I read a great fact sheet (from Canada) on the lifecycle of the Onion Maggot and will have to monitor the next few months as they can have three generations of maggots in one year!

Fields of "Screaming" Onions

Fields of “Screaming” Onions

Opening up the Onion and you can find the Onion Maggot.

Opening up the Onion and you can find the Onion Maggot.

And another Onion Maggot.

And another Onion Maggot.

And another Maggot.

And another Maggot Larvae.

 

Quite a few maggots although I only seem to find one per onion: maybe they're territorial?

Quite a few maggots although I only seem to find one larvae per onion: maybe they’re territorial?

 

 

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