Cabbage root fly

[lukens]

So, it seems I'm under attack.

I had my suspicions when three cabbage seedlings went, and a kohlrabi started wilting, but I could find no culprits in the soil. Now though 14 of my 25 turnip seedlings have wilted, and I've found smug looking maggots at the base of each one. Most other brassicas in the same bed (a 4x4ft square foot gardening bed) had maggots at the roots too. They also look very much like the maggots that took out one of my sweetcorn, is it possible they chanced that too?

Is there anything I can do? I've watered all my beds with Nemasys Grow Your Own. Has anyone had any luck with this? I've also checked round all my brassicas, and picked out all the maggots I could find.

I do have mesh that I was going to fit over my beds, but now the maggots are here, is it too late? I couldn't find any maggots in my othe bed with brassicas in, should I mesh that one sharpish?

So frustrating. I also have a range of oriental brassica seeds I was going to plant out later in summer, should I just give up on that idea? Would I be OK if started indoors in modules, then planted out with collars in squares that hadn't had brassicas in? (they'd need to be different squares in the same beds, probably).

[WendyC]

How frustrating! I've never had problem with cabbage root fly but always use cabbage collars when planting out.
Looked in my Pippa Greenwood book of all things creepy crawly. She says maggots are white, legless up to 9mm long. no insecticides for use but recommends cabbage collars when planting out. The female fly lays eggs on the soil around the stems of plants, so if using collars she'll lay on the collars not the soil and the eggs dry out.
My guess is that if you plant away from the original planting no eggs will have been laid so should be clear of maggots in the soil. No mention of sweetcorn attack but all in brassica family. Mesh would also help. Are you sure is it cabbage root fly?

[lukens]

Not 100% sure if they're cabbage root fly, but (other than the sweetcorn, which could have been something different) they seem to be favouring plants in the cabbage family. Turnips, radish, cabbage family seedlings in a salad mix, calabrese, etc.

I've had to take all my turnip seedlings out. Not sure whether to sow any more, in a different place, as can't really use collars on them.

I tried getting my mesh netting over the hoops on another bed, but gave up. It was a bit of a wrestling match. I may have to shell out for fitted ones, or have a go with the sewing machine.