Caterpillars on my Cauliflowers

Hi all

Whilst checking over my veg today I noticed some little holes on my cauliflower leaves, underneath are tiny little green caterpillars, whats the best way to get rid of them?? Theres no way I'm going to be able to pick them off!

 

I'm doing battle with caterpillars too, amymac. I've got a product (not a chemical) called Bacillus thuringiensis which I'm trying for the first time and so far seems to be working. You mix up the powder with water in a sprayer and spray the plants both for prevention and cure. Might be worth a look in your local garden centre?http://en.wikipedia.org/wiki/Bacillus_thuringiensis

 

Reminds me of when I grew some. Only realised there were caterpillars when I was tucking in
A bit late now, but the best thing is to prevent in the first place by using fine mesh netting.