Florida is home to three species of tussock moth caterpillars: the fir tussock moth, the white-marked tussock moth, and the definite tussock moth. These colorful, densely hairy caterpillars show up on trees and shrubs starting in late winter, and while they look fascinating, their hairs can cause painful skin reactions. If you’ve spotted one on your property or accidentally touched one, here’s what you need to know.
Species Found in Florida
The fir tussock moth is the most common species in the state, with the white-marked tussock moth a close second. The definite tussock moth is very rare. All three share a similar body plan: dense tufts of hair (called tussocks) sprouting from the body, often in dramatic white, yellow, or orange clumps, with a distinctive look that’s hard to confuse with other caterpillars. The white-marked tussock moth, in particular, has a bright red head, four white brush-like tufts along its back, and two longer black hair pencils projecting forward like antennae.
When They Appear
Tussock moth caterpillars hatch from eggs in late February or early March in Florida. They feed actively through March, and by early April they’ve matured and begun spinning cocoons. That gives you roughly a six-week window when caterpillars are crawling on trees, fences, sidewalks, outdoor furniture, and the sides of buildings. Because Florida’s climate is warm, this timeline can shift slightly from year to year.
The short season is worth paying attention to, because the risk doesn’t end when the caterpillars disappear. Their irritating hairs get woven into cocoons and can also transfer to egg masses. Wind can detach and scatter these hairs across surfaces, and in some species, the hairs remain irritating in the environment for at least a year. So a fuzzy cocoon stuck to a tree trunk months after caterpillar season can still cause a reaction if you handle it.
What Happens if You Touch One
Tussock moth caterpillars are covered in urticating hairs, tiny barbed structures that break off on contact and lodge in your skin. The hairs are directly irritating and can also transmit mild toxins. You don’t even have to pick one up. Brushing against a caterpillar on a branch, leaning on a railing where one has crawled, or handling a cocoon can all transfer hairs to your skin.
The most common reaction is localized: pain, redness, and small raised bumps or welts at the contact site. Mild cases resolve within an hour. More moderate reactions include itchy, scaly, or blistering patches that can look like eczema and persist for weeks. The severity depends on how much contact you had, where on your body it occurred, and your individual sensitivity. People who’ve had previous reactions sometimes respond more intensely on repeat exposure.
If you touch your eyes or mouth after handling a caterpillar, the reaction can be more serious, potentially including shortness of breath and difficulty swallowing. Anaphylactic reactions have been reported, though they’re rare. Children and pets are at higher risk simply because they’re more likely to pick caterpillars up or rub their faces afterward.
Treating a Rash
If you’ve made contact, the first step is removing as many hairs as possible. Press a strip of adhesive tape against the affected skin and peel it off repeatedly to pull out embedded hairs. Wash the area with soap and water. Avoid scratching, which drives the barbs deeper. Over-the-counter hydrocortisone cream and oral antihistamines help with itching and swelling. If a rash spreads, blisters badly, or you develop any breathing difficulty, that warrants medical attention.
Damage to Trees and Landscaping
Tussock moth caterpillars are generalist feeders. The white-marked tussock moth alone has been recorded feeding on over 140 woody plant species, including oaks, maples, and various conifers. The definite tussock moth prefers willow but also feeds on oak, maple, hackberry, and birch. In Florida, live oaks and other landscape trees are common hosts.
A healthy, mature tree can typically bounce back from even heavy defoliation in a single season. The real concern is for trees already stressed by drought, disease, root damage, or repeated years of caterpillar feeding. For these trees, a bad caterpillar year can push them into decline. Recently planted young trees are especially vulnerable, since a single season of significant leaf loss can set back their establishment and overall health.
How to Manage Them Safely
Because the caterpillar season is short, lasting roughly from late February through early April, many homeowners simply wait it out. If you need to remove caterpillars from a small tree or outdoor surface, wear gloves and long sleeves. Pick them off with tongs or a stick and drop them into a bucket of soapy water. Never handle them with bare hands, and wash any clothing that contacts them separately to avoid transferring hairs.
For larger infestations, a biological pesticide containing Bacillus thuringiensis (Bt) is effective against young caterpillars and safe for other wildlife. It works best when caterpillars are small, so early March is the ideal window in most of Florida. Older, larger caterpillars are harder to control with any method.
Keep an eye out for egg masses and cocoons on tree trunks, branches, fences, and building walls. These fuzzy, tan or white clumps are easy to spot and can be scraped off and disposed of, but use gloves. The urticating hairs embedded in cocoons and egg coverings remain irritating long after the caterpillars are gone. If you’re pruning branches with visible cocoons in summer or fall, the same precautions apply: gloves, long sleeves, and avoiding contact with your face.
Natural predators help keep populations in check. Parasitic wasps and flies attack tussock moth caterpillars, and birds eat them despite the hairs. Avoiding broad-spectrum insecticides in your yard helps preserve these natural controls and reduces the chance of a population boom the following year.