[Sadgit]

Just a a really good harvest of various veg/fruit. I washed the broc really well and the missus does the chopping, and I do the cooking. Anyway she found a caterpillar on one of the broc and is oh so squeemish, and then I found about 10 of the *. This could put her off home grown veg for life.

How do I stop them arriving in the 1st place? or is it "just one of those things" ?

Chemicals? Magic?

Cheers
SG

[Heather_S]

Fleece covering, placed very very securely so the butterflies can't come in and lay their eggs. Of course my fleece kept blowing away so I got more caterpillars than anything.

[GrannieAnnie]

I bought some pond and crop netting from Wilko's, which said butterflies can't enter!!!!  Ask Mellowmick, he has seen them metamorphasize (sp?) through the tiny holes, and I have seen one fold up its wings to get out as I was chasing it with a big stick at the time!!!

But saying that, although I have got a few caterpillars inside the netting, which is over a framework of black tubing stick into canes which are then stuck in the ground, I've had my best year so far for brassicas.  Mind you, caterpillars have eaten much of the brassicas I tried in my polytunnel which isn't netted and the savoys I planted a couple of weeks ago, which are not netted because I can't afford to buy any more at the moment!

Fleece is good, but when I tried it, I didn't do it properly, and everytime it rained my fleece fell down in the middle and loads of weeds grew, because I just covered the seeds and left them alone. (This was in my first year, when I was still very much a novice!)  Next year, hopefully things will be even better!

[Sadgit]

ahhh well I have fleece, but only used it from a month to 6 weeks ago maybe 8 (god time flys) but I keep finding up to 5 cabbage whites under it, so I'm guessing that eggs were laid before I had the fleece up and since then they keep breeding under it?

[Oliver]

but I keep finding up to 5 cabbage whites under it, so I'm guessing that eggs were laid before I had the fleece up and since then they keep breeding under it?

You are probably right that the eggs were laid before you put the fleece on and the eggs are now hatching into caterpillars that are eating your produce.

So, under the fleece: The caterpillars will grow, eating the brassicas all the while, and after shedding their skin several times, they form a pupa. After abou 3 weeks a new butterfly emerges. This butterfly then flies off to feed on nectar and find a mate and the whole process begins again. If you do not release the butterflies they will probably die before they lay more eggs because there will be no food for them under the fleece - they need nectar.

Are you sure they can't get under the fleece somehow?  - When a butterfly has to do what a butterfly has to do it is quite amazing how 'resourceful' they can be. They will even lay their eggs through enviromesh (a very fine netting - like a net curtain) onto any brassica leaves that are toughing the netting.

They do a regular egg patrol - look under the brassica leaves for the eggs and then squash them. So far there are no caterpillars on the purple sprouting. Last year they made quite mess of the plants - Looked pretty awful but the plants did recover.

[mellowmick]

Ask Mellowmick

I'd used the cheap green plastic monofilament netting from the 99p shop. It seems that if you stretch it too much, the mesh becomes wide enough to let cabbage whites through. Apparently there are large whites, which have the yellowish caterpillars with the black stripes down the back, and the small whites, which have the green ones.
Dead frustrating. I have to take all the netting down and pick them off every week or so, then put it all back up again. Collected two dozen last Sunday.
I have 10 sheets of 5'x6' metal mesh which I'll be using as a brassica cage next year, with netting draped over it, rather than pulled tight, or even old scaffolding netting, which has a much finer mesh.
Not sure what damage they've actually done, because the real effect will be in the heart of the growing head, rather than the large outer leaves. :cry:

[John]

Systemic insecticide spray is effective and you can get sprays for caterpillers but do YOU want to eat the produce after?

I always say that if it is not good enough for the bugs, it's not good enough for me and I'd rather have to wash off a beastie than eat a tasteless, invisible poison.

[milkman]

viromesh is the answer!!!