Common buckeye

by Elora Pfriender

“Know your native pollinators” is a series of articles that will help you identify and appreciate Florida’s varied pollinators, including bees, wasps, butterflies, moths, beetles, flies, birds and bats. Pictured above: Common buckeye (Junonia coenia) by Emily Bell.

Despite this butterfly’s intimidating eyespots and tendency to chase passing objects, the Common buckeye is anything but aggressive.

CLASSIFICATION

Class: Insecta
Order: Lepidoptera
Family: Nymphalidae
Subfamily: Theclinae
Genus species: Junonia coenia

FUN FACT

Adult Common buckeyes can learn to recognize which flowers provide the most nectar based on petal color. This ability is not instinctive but developed through trial and error while nectaring. The flowers benefit as well — since butterflies linger longer to consume all the nectar, they collect and transfer more pollen in the process. This interaction is an example of mutualism, a mutually beneficial relationship between Common buckeyes and flowering plants.

IDENTIFICATION

Wings open straight on view of Common buckeye butterfly. Body and wings are brown. Forewings have two orange bars and a thick creamy white strip along with one large and one small eyespot. Hindwings have two large eyespots and are orange toward the end.
Common buckeye butterfly. Photo by Emily Bell

The Common buckeye is the most widespread of Florida’s buckeye butterflies, found in all 67 counties. It closely resembles — and may even hybridize with — the state’s two other buckeye species: the West Indian mangrove buckeye (Junonia neildi) and the Northern tropical buckeye (Junonia zonalis), both of which have much smaller ranges. While the three species share many visual similarities, most buckeyes found outside coastal areas or the southernmost parts of Florida are Common buckeyes.

The Common buckeye has a wingspan of 32–60 mm, with females generally larger than males. When the wings are open, the dorsal side displays a brown base with striking orange bars and two eyespots on each wing — one large and bordered by a white band, the other smaller and more distal. These markings resemble eyes and serve to scare or distract predators. The ventral hindwing shifts in color with the seasons, appearing light brown with dark spots in summer and deepening to a reddish-brown in winter.

FORAGING PREFERENCES

Plantains (Plantago spp.) are the preferred host plants of Common buckeyes. Several of these flowering herbaceous plants are native to Florida, with the Virginia plantain (Plantago virginica) being the most widespread. Other native host plants for Common buckeyes include American bluehearts (Buchnera americana), False foxglove (Agalinis spp.), Blue toadflax (Linaria floridana), Frogfruit (Phyla nodiflora) and Oblongleaf twinflower (Dyschoriste oblongifolia). Adult Common buckeyes nectar primarily on composites and small flowers, including native species of aster and dogbane.

HABITAT

Common buckeyes are found throughout the continental United States, Mexico and the southernmost parts of Canada. Starting in late summer or fall, adults pause reproduction and migrate south to overwinter. In Florida, they can be found year-round. Common buckeyes enjoy wide open, sunny areas like agricultural fields, gardens, scrub, pine savannas — and maybe even your front yard!

DID YOU KNOW?

During migration, male Common buckeyes fly ahead of the females, waiting for them in open, flat areas near the ground. When they spot insects, animals or other moving objects overhead, they instinctively give chase. While this behavior may seem territorial, it is actually a strategy for locating potential mates.

LIFE CYCLE

Females lay round, dark green eggs individually on the leaves of their host plants. Larvae are black with white and orange markings and are covered in branched black spines. Common buckeye chrysalises are brown with darker markings, though their shade varies based on light exposure during pupation — caterpillars that pupate in bright areas develop lighter brown chrysalises, while those in darker environments produce darker ones.

A Common buckeye caterpillar with spiky bristles and orange markings is curved around a plant stem with small buds, set against a blurred green background.
Common buckeye caterpillar. Photo by Emily Bell

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