Diamond Back Moth larvae on broccoli and cauliflower.

I have had my broccoli and cauliflower under netting since it came outside to harden off. This week I have noticed small holes in the leaves, further investigation today shows that I have tiny caterpillars on the underside merrily munching away. I've googled them, and they are definitely DBM larvae.  I've removed as many as I can by hand, but is there anything else I can do?