I am having my leeks attacked by the Allium leaf mining fly Phytomza gymnostoma. It lays eggs that hatch into a small brown grub that is found in the leek when harvested, and there are brown streaks and damage inside the leek. 2 out of 3 autumn leeks :(harvested recently have been affected and not usable. It was apparently found in the West Midlands in 2003 and has slowly migrated to the east Midlands, I am at Littleover Lane in Derby. Has anyone any good tips for stopping it destroying the whole crop? Leeks have always been a really good winter crop for me but this looks like it may stop that.
I am afraid here in the West Midlands we all have to cover our leeks a soon as planted with enviromesh, harvesting becomes a bit cumbersome but its worth it to get good quality leeks.
I don't know enough about the season/laying habit of this fly, I know they like freshly prepared soil so I always leave the prepared soil a few days before planting but really not sure it there is anything you can do now ie is the damage already done or is it worth covering the crop.
Sorry someone will be along later with an answer to that - hope you get something from this years crop!
Thanks for the info. I have avoided getting Enviromesh as it is a bit costly, but I shall have to save up I think! I have looked at the DEFRA advice on this pest and the advice is to protect in February. Flies have two laying seasons. The advice is at http://www.fera.defra.gov.uk/plants/plantHealth/pestsDiseases/praTableNew.cfm , This is a list look for Phytomza gymnostoma (leaf mining fly).
It seems that there is a double strike going on.
http://www.growsonyou.com/Sid/blog/2316-leek-moth-and-allium-leaf-mining-fly-the-sequel
Haven't yet decided what has got mine.
Grrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
OC
I fleeced my onions this year, until they got to a reasonable size, at which point the fleece disintegrated and left horrible bits of fluff all over the plot. Re-using the stuff doesn't seem to work, but the onions were fine.
Thanks for the warning, Palladium, I'm about 8 miles west of you so I expect it'll be here by next year. Sounds a horrible pest, hope you can salvage something from your crop.
we are in the west midlands and pulled up some of our leeks the other day and they were fine, pulled some up today and this "fly" has managed to attack all 6 of them, not happy i was making a nice stew. Should have used my brain though to be honest because i had the same thing happen to the onions a month or two back :( :'( will be covering next year
If you can`t afford Enviromesh, then get some Fibre Fleece from your local garden centre, It`s a lot cheaper and should do just the same job. :)
Thanks for the link Palladium, and welcome to A4A... as I said at the AGM on Thursday I've got it too.... :(
AGM? How`d it go then?