The Gulf fritillary or passion butterfly (Dione vanillae) is a bright orange butterfly in the subfamily Heliconiinae of the family Nymphalidae. That subfamily was formerly set apart as a separate family, the Heliconiidae. The Heliconiinae are "longwing butterflies", which have long, narrow wings compared to other butterflies.
Dione vanillae is most commonly found in the southern areas of the United States, specifically in many regions of Florida and Texas.
Gulf fritillaries have a chemical defense mechanism in which they release odorous chemicals in response to predator sightings. As a result, common predators learn to avoid this species. Pheromones play a critical role in male-female courtship behaviors, with male gulf fritillaries emitting sex pheromones that contribute to mate choice in females.
Gulf fritillaries are found primarily in the southern parts of the contiguous United States, from Florida and Georgia to Texas and California. However, this butterfly’s range can extend from the Southern United States into parts of Mexico and Central America and sometimes as far as parts of South America. They are also found in Hawaii.
Gulf fritillaries are found in open habitats, like in moderately sunny areas near open grasslands, parks, and woodlands. Gulf fritillaries are also commonly seen in local butterfly gardens across the U.S.
The general process for a typical courtship interaction begins when a male flies and lands near a perching female, who is most likely perched on a host plant, such as several species of the Passiflora genus. Once the male has landed, the male assumes a position next to the female with their heads together and with their bodies aligned at a 45-degree angle. At this time, the male engages in a specific action called the wing clap display in which the male continuously claps its wings open and closed. During this time, the antennae of the female are placed between the opening and closing wings. After the male ceases wing movement, the male butterfly will move into a position that facilitates genital contact with the female. The average duration of the copulation process including the wing clap display is approximately 11 seconds.