When you hear the name orange dog, an odd colored canine may come to mind. But the orange dog caterpillar is actually a citrus tree pest in Naples FL. During the months of August and September the giant swallowtail butterfly will swarm citrus trees laying eggs on the leaves which will hatch to become orange dog caterpillars. The orange dog caterpillar looks like a bird dropping and has two antennae that will protrude when threatened emitting a rancid smell. It is during this phase that the orange dog caterpillar will feed on the leaves of the tree. As it grows it will consume an ever increasing amount of foliage until it pupates.
Control methods consist of manual removal or spraying the tree leaves with a bt insecticide. The bt is not a chemical but actually a bacteria that the orange dog caterpillar will ingest while feeding on the sprayed leaves and consequently die. They are most prevalent in late summer when the butterfly is actively laying eggs