The zebra longwing butterfly (Heliconius charitonius) was designated the official state butterfly of Florida in 1996. The zebra longwing butterfly is found throughout Florida in hardwood hammocks, thickets, gardens, and particularly in the Everglades National Park.

This butterfly is characterized by long black wings with distinctive thin stripes and a slow, graceful flight. It makes a creaking sound when alarmed. Zebra longwings feed on nectar and pollen (the only butterflies known to eat pollen, which is probably why they have a long lifespan (about six months, as compared to a more usual one month for other butterfly species).

The zebra longwing butterfly lays its eggs on passion vine leaves. Passion vines contain toxins that are consumed by the caterpillars, which make the adult butterflies poisonous to predators.

Source:

State Symbols: Florida Kids, My Florida.com
The Zebra Longwing: Native Florida, Your Florida Backyard

Links:

State Insects - 50 States List