Beware the Itchy Invaders: These Caterpillars Cause Skin Reactions Across Florida

Tussock moth caterpillars are popping up throughout Florida. Health officials warn that touching these insects can trigger rashes and irritation. Oviedo, a city in Seminole County, has urged residents to stay alert as the creatures descend from oak trees searching for spots to spin cocoons.

The caterpillars hatch in February. By early April, they've grown to full size and abandon their oak tree homes, hunting for places to build cocoons before changing into moths.

The Florida Department of Health says direct contact with the caterpillar, its hairs, or its cocoon can spark an allergic reaction that produces an itchy rash. The hairs have barbs and latch onto skin, which makes removal difficult.

"Those hairs can poke into the skin and then break off," said Joyce Fassbender, an entomologist at FGCU, according to WESH. "So they're called urticating hairs, but that's what they do. It's a defense mechanism. It's compared to fiberglass."

Parents should make sure children don't touch or play with the caterpillars. Kids playing outside may encounter them around trees and playground equipment this time of year.

If someone comes in contact with the insects, health officials suggest removing the caterpillar without using bare hands. Press tape over the exposed area with the sticky side facing the skin, then pull up the tape to extract any hairs or spines. Repeat with fresh pieces of tape as needed.

Wash the area with soap and water after removing the hairs. Press an ice pack against the skin to reduce stinging. Mix baking soda and water into a paste to lessen itchiness.

Fassbender warns against spraying oak trees if caterpillars appear on them. "If you spray your oak tree, you're spraying and killing all the food to feed our birds," Fassbender said.

By late April or early May, most caterpillars will have spun cocoons. The cocoons still contain the irritating hairs, so people should keep avoiding them.

Anyone whose rash doesn't go away, worsens, or develops severe blisters should talk to a healthcare provider. Pets are protected by their fur, according to experts.