Zebra Longwing Caterpillar

The zebra longwing caterpillar is the larval stage of Heliconius charithonia, the striking black-and-yellow-striped butterfly that is the official state butterfly of Florida. It belongs to a group of tropical butterflies known for long lifespans, gregarious roosting as adults, and larvae that feed exclusively on passionflower vines (Passiflora species), from which they sequester cyanogenic compounds that make both larvae and adults unpalatable to many predators.

Zebra longwing caterpillars are found in warm, humid habitats throughout Florida, the Gulf Coast, and much of Central America and the Caribbean, wherever host passionflower vines are present in hammocks, gardens, and forest edges.

• Body pale white to cream, marked with numerous small black spots and speckles
• Covered in rows of long, branching black spines along the back and sides, giving a bristly but non-stinging appearance
• Head capsule pale with black markings
• Mature larvae reach roughly 1 to 1.2 inches (25-30 mm)
• Found feeding on the leaves, tendrils, and growing tips of passionflower vines, sometimes in small groups on the same plant

This caterpillar occurs wherever passionflower vines grow, including tropical hammocks, forest edges, fence lines, and gardens throughout Florida, the Gulf Coast states, the Caribbean, and Central America into South America. Because the climate in much of its range stays warm year-round, larvae can be present in nearly every month, with populations tracking the availability of fresh passionflower growth.

Larvae feed on the leaves and tender shoots of passionflower vines, sometimes stripping a vine heavily where populations are dense, and can consume eggs or other larvae of their own species when food is scarce. By sequestering cyanogenic glycosides from their passionflower hosts, the caterpillars and the resulting long-lived, black-and-yellow adult butterflies gain a chemical defense that makes them unappealing to many predators. As specialist herbivores of Passiflora, zebra longwing caterpillars help regulate vine growth locally and represent an important link between passionflower plants and the pollinators and predators that interact with the adult butterflies.

Eggs are laid singly or in small groups on new growth of passionflower vines and hatch within a few days. Larvae pass through several instars while feeding on the host plant, molting and growing over roughly two to three weeks in warm conditions. Mature caterpillars form a distinctive angular, leaf-like chrysalis suspended by a silk pad from a stem or nearby structure. In frost-free regions the species breeds continuously with overlapping generations year-round, while in cooler parts of its range activity slows or pauses during the coolest months.