The Cassius Blue butterfly Leptotes cassius is found in the southeastern US, primarily in Texas and Florida.
Cassius Blue butterflies are small butterflies, found flying near Plumbago plants. Plumbago, also called Leadwort, is the host for this species. Butterflies lay eggs on the bloom buds and bloom spikes. The small green caterpillars look like the bloom buds. They are well camouflaged.
One of Marc Minno’s fantastic books explains the method of finding Cassius Blue caterpillars. They are so well camouflaged in the bloom buds that they are nearly impossible to find on the plant itself.
To find the caterpillars, simply pick off some of the bloom spikes and place them in a clear container. The following day, pick up the container and look underneath. If you see frass, you know a caterpillar is inside the container. Simply open the lid and look closely in the area above the frass. They are easily raised on cut bloom spikes.