[upert]

build a birdbox; blue tits, for one, will scoff their way through caterpillars like they're going outa style over the breeding season. make sure your box meets the rspb/bto specs and place it somewhere out of the way then you may eat your brassicas instead of the caterpillars having the lot.

[mumofstig]

The birds don't like to eat cabbage white caterpillars because they don't taste nice to them.

Eat a lot of other nasties for you    but not those, sadly.

[shaun]

thats very good but how do the birds get through the netting that you have put over your brassicas to keep the pigeons off  :?

[outmowed]

Blue tits will gorge on greenfly and other flying things.

[upert]

haha i haven't thought this through have i? except i have a bit, there's lots of people on my site who leave their brassicas un-netted; one bloke by me had all his cauli leaves and cabbages munched. he had a lot of caterpillars. another guy's nets kept out pigeons but not the butterflies.

besides the other pests they'll eat i'm making a mealworm feeder via which i'll provide live food. i'm rather keen on building stuff over this relatively quiet bit of the veg grower's year.

[shaun]

those butterflys will lay the eggs onto the netting more so if the leaves of your brassicas are touching the net .
leave ours un-netted and they will be just stalks within an hour of leaving

[DD.]

My nets have small enough mesh to keep out both!

[Faz]

Don't forget to plant some flowers (marigolds or whatever) to attract buzzy bees and hoverflies. As well as pollinating stuff the hoverfly larvae will also eat greenfly. I had loads of their babies in my greenhouse last year and barely any greenfly.