Q: I found this in my tomatoes. How can I safely get rid of them?
A: It is a fat and sassy tomato fruitworm. It would have continued devouring the inside of the tomato if you had not found him. The brown/green stuff is his poop.
The best control is a combination of monitoring your tomatoes and spraying organic insecticide.
As soon as the first tiny fruit are seen, inspect the tips of leaves nearby. Fruitworm eggs are tiny and white. When the eggs hatch, the small caterpillars head for green fruit and start chewing. If you spot them early, you can simply mash the eggs with your fingers.
The best insecticide is Bacillus thuringiensis, abbreviated Bt. There are several brands that contain Bt, so read the label.
Spray according to label directions in the evening, since the insecticide is broken down by light.
If the caterpillar seems to have just begun damaging the tomato, you can cut out the damage and eat the rest of the fruit. Once they have gone inside the tomato, it’s too nasty to consume.