This fuzzy green caterpillar is about 2 to 3 inches long and is as thick as my finger. Has rings of prickly spikes (ouch.) About five of these guys are devouring every leaf on my hibiscus plant. I’m leaving them alone, hoping they’ll be butterflies and not awful pests. I am in Fort Lauderdale, Florida.
Your beautiful caterpillars are Io moth caterpillars, one member of the Silk moth family.
They feed on a wide variety of plants other than hibiscus including birches, clover, corn, elms, maples, oaks, willows, roses, cotton, azaleas, palms, and even some grasses. Not sure if you have some of these plants nearby to get them to move onto.
They are not a pest…they will not kill your hibiscus. Please just let them finish their development.
The caterpillars stay in clusters early on, but go off alone as they mature. Your caterpillar looks like it may be mature and will leave the hibiscus soon to form a papery cocoon, usually in leaf litter. There may be up to four generations in the south(you are so lucky!!), but usually just one in the north(not so lucky for us up north!).
Caution: As you noticed the caterpillars may “sting” if handled. The larger the caterpillar the more intense the stinging sensation caused by the spines.
So glad you checked on this one…it is a great insect to have….even tho you have lost a few leaves of your hibiscus….they will grow back.:-)