Tomato Invaders have Arrived

I've been very light handed with the organic bug spray on the vegetable garden, and now I'm paying the price for it. The tomato invaders have arrived. As I was watering the tomato plants and getting ready to stake them out some support to hold their heavy boughs, I spotted a plump green caterpillar on the top soil. I checked my one little green tomato and something was poking its little brown caterpillar head (or bottom??) out. Dang. I plucked the plump Caterpillar from the ground and then plucked my little tomato from the vine. Looking through the green leaves I found another little green caterpillar, got the spray out and doused the plants but good. Take that tomato invaders.