Stinging Caterpillars in South Florida: Which Ones to Avoid and What to Do If You're Stung

Caterpillar sting first aid — especially for the puss caterpillar (most severe): (1) Do NOT rub the area — rubbing embeds spine fragments deeper into skin and worsens the reaction. (2) Remove spines with tape — apply clear tape (not duct tape) to the sting site and pull it off to remove embedded spine fragments. Repeat with fresh tape until no more spines are removed. A fine comb can also help lift spine clusters from skin. (3) Wash thoroughly — wash the affected area with soap and water after removing spines. (4) Ice pack — apply ice wrapped in cloth to reduce pain and inflammation. Do not apply directly to skin. (5) OTC antihistamine — diphenhydramine (Benadryl) for systemic allergic component. (6) OTC pain reliever — ibuprofen or acetaminophen for pain. (7) Hydrocortisone cream — topical steroid to reduce local inflammation after spines are removed. For puss caterpillar stings specifically (the most dangerous native caterpillar in North America): severe immediate pain, possible spreading numbness, nausea, fever, and shock reactions have been documented. Seek emergency medical care if: symptoms spread beyond the sting site rapidly, you experience difficulty breathing, your face or throat swells, or you feel lightheaded or nauseated. Florida Poison Control: 1-800-222-1222.

Stinging caterpillar season in South Florida varies by species: (1) Puss caterpillar (puss moth/asp): Peak season in South Florida is August through November — the second-generation puss caterpillar population that develops during and after the wet season. These caterpillars are found on oak trees throughout Broward and Palm Beach County neighborhoods during this period. Many South Florida school districts issue alerts in September–October when children come in contact with puss caterpillars on school grounds. (2) Saddleback caterpillar: Present summer through fall, peak August–October. Common in ornamental plantings and garden areas. (3) IO moth caterpillar: Multiple annual generations, found spring through late fall. The most broadly distributed stinging caterpillar in South Florida residential areas. (4) Buck moth caterpillar: Spring emergence (March–May in South Florida) when larvae hatch and feed on oak trees before pupating. Buck moth caterpillars fall from oak trees and can sting when stepped on barefoot on sidewalks or lawns beneath oaks. (5) Climate factor: South Florida's mild winters allow some stinging caterpillar species to have more generations per year than their northern counterparts. The extended warm season means exposure risk lasts longer than in other US states.

Stinging caterpillars in South Florida are native insects whose populations cycle naturally and are influenced by host plant availability: (1) Primary host: Oak trees are the most important host plants for the most dangerous South Florida stinging caterpillars — puss caterpillars, buck moths, and spiny oak slug caterpillars all depend on oak trees. South Florida's extensive mature live oak canopy (present throughout Broward and Palm Beach County residential neighborhoods) provides abundant host plant for these species. (2) The connection to property landscaping: Puss caterpillars are also found on citrus, rose, and various ornamental plants in yards. Saddleback caterpillars use a very wide range of host plants including ornamental palms. IO moth caterpillars use many landscape shrub and tree species. This means caterpillar encounters occur not just under oaks but in landscaped yards. (3) Population variability: Stinging caterpillar populations fluctuate year to year based on weather patterns, natural predator populations, and disease. Some years produce notably more severe outbreaks than others. (4) No evidence of long-term worsening, but increased awareness: South Florida's increasing population and residential landscaping expansion means more people encounter stinging caterpillars — and more reporting creates the impression of worsening populations even when actual insect numbers are stable.

Prevention for families with children in South Florida: (1) Teach identification — the most important prevention measure is teaching children to recognize common South Florida stinging caterpillars. The puss caterpillar looks like a fuzzy piece of fur or a hair scrunchie; it is attractive to children and may be picked up. Teach 'never touch fuzzy caterpillars.' (2) Yard inspection under oaks — during August–November, inspect areas beneath oak trees before allowing barefoot activity. Puss caterpillars and buck moth caterpillars fall from oaks and can sting when stepped on. (3) Footwear under oak canopy — require shoes or sandals for outdoor activity under mature oak trees during peak caterpillar season. (4) Check outdoor furniture — stinging caterpillars can be found resting on outdoor furniture, play equipment, and railings beneath or near host trees. Check before children use these surfaces during peak season. (5) Check clothing before putting on — caterpillars on clothing hanging outdoors or stored in garages can sting when clothing is put on without inspection. (6) Garden gloves always when gardening — the saddleback and IO moth caterpillars occur in ornamental plantings; always wear garden gloves and long sleeves when working in planted areas during summer and fall. (7) School awareness: If your child's school has oak trees on the property, be aware that September–October is peak puss caterpillar season in South Florida and school-ground encounters are common.