Frangipani hornworm, Pseudosphinx tetrio
I believe your caterpillar is the Frangipani hornworm, Pseudosphinx tetrio. It is a common moth in the American tropics and subtropics although can occasionally be found in southern parts of Florida. The adult moths are mostly a drab grey coloration and are a stark contrast to their colorful larvae. These larvae are conspicuous, large caterpillars often occurring in gardens feeding on frangipani and other members of the dogbane family (Apocynaceae). The caterpillar can grow up to 6 inches in length. The caterpillar is black with yellow stripes and it has a red-orange head. The unique color combination of the caterpillar is aposematic which means the colors warn any potential predator the caterpillar is toxic.
Females moths lay approximately 50 to 100 eggs in clusters on leaves of the host tree. Tetrio sphinx caterpillars often appear in gardens or landscaping and can defoliate frangipani trees in a few days or couple of weeks. One caterpillar can devour three large leaves per day. They typically start feeding from the leaf tip and have been known to feed on tree stems if leaves are unavailable. Frangipani hornworms can be found from July to September in southern Florida. Hand-picking larvae is probably the best way to eliminate them from tree. Their presence and feeding habits typically do not cause severe damage to host plants which will typically survive the caterpillar’s defoliation. For more complete information on the caterpillar please read the University of Florida publication: https://edis.ifas.ufl.edu/in621