Congratulations! Your tree could be the larval host of one of the most beautiful butterflies of all - the Giant Swallowtail. It's babies (caterpillars) feed on citrus leaves here in the Southwest. Usually they don't do much damage just a little munching here and there. A large tree can tolerate it, but newly planted ones may need your help. Just pick off the caterpillars (which look like bird droppings) and place them on a larger tree or discard them.

No other control is needed.

Here is a link that might be useful: Giant Swallowtail butterfly

Yes what's aztreelvr said. I've been picking them off of my citrus trees lately. The butterflies sure are pretty but I've been shoeing them off of my yard whenever I see them.