All of the cabbage white caterpillars that I brought inside to raise ended up already being parasitized by the wasps in the picture. I estimate that each caterpillar was the host to 15 – 20 wasps. No wonder we don’t see more butterflies in the garden.
Butterfly Gardening 
Quite interesting, Tom. I’ve heard of predatory wasps but never sure what they looked like. Thanks for sharing.
Poor cabbage whites!