Common Buckeye

Media
Common buckeye butterfly nectaring on a flower, wings spread
Scientific Name
Junonia coenia
Family
Nymphalidae (brushfooted butterflies)
Description

Adult common buckeyes are mostly brown above with two orange bars on the leading edge of the forewing and an off-white forewing band. All four wings have eyespots. From below, the hindwing is brown with small or absent eyespots, and the forewing pattern is similar to that of the dorsal side. Fall individuals frequently have a reddish tint below.

The caterpillars are usually bluish black, with yellow to creamy orange stripes and spots and numerous metallic bluish-black, short-branching spines. The spines on the sides emerge from raised orange spots. The head is black with an orange top.

Similar species: The bold color pattern and eyespots make the common buckeye pretty easy to identify. There is another species that looks a little like a washed-out buckeye, and that's the white peacock (Anartia jatrophae), which is a southern species that rarely strays into Missouri. Compared to buckeyes, it is very pale. Its upperside eyespots are much smaller than the buckeye's large, bold eyespots. From below, it can be distinguished from pale-colored buckeyes by the point on its hindwing.

Size
Wingspan: 1½–2½ inches.
Where To Find
image of Common Buckeye Distribution Map
Statewide.
Occurs in all kinds of open, sunny habitats. The abundance of this species varies from year to year. Some years it is very common, and in other years it is almost absent.

Larvae feed mostly on verbenas, plantains, toadflax, ruellias, and snapdragons. Toxic chemicals from host plants protect caterpillars from predators, but because these plants are harder to digest, the caterpillars need to eat more than they would if feeding on plants with fewer such chemicals.

The adults visit a variety of flowers, especially ones in the aster-sunflower-daisy family. Other favorites include members of the dogbane-milkweed family and the mints. They are also attracted to decaying fruit and moist places.

A breeding summer resident.
Life Cycle

Adults fly from spring through fall, with several broods during this time. This species does not survive typical Missouri winters and must repopulate our state each spring from populations that survive winters in the Deep South. Once here, they breed and repopulate our state until freezes kill them off in the fall.

Males perch on low vegetation, or on the ground, to wait for females to fly near. The males are territorial and frequently chase away other insects that fly near. Eggs are laid singly on buds and upper sides of leaves of host plants. The caterpillars are solitary.

Although many butterflies are named for their food plants, this remarkably attractive butterfly is named for the bold eyespots on its wings, and not for any relationship to the trees called buckeyes. In this case, beauty trumps ecology!

Butterfly watching has become an increasingly popular outdoor recreational activity. It is a lot like bird watching, with clubs, checklists, and festivals. People use binoculars, cameras, and field guides to ID and record their sightings. Annual butterfly counts, organized by entomologists and performed by teams of amateurs, are a fun way for nonscientists to contribute in a meaningful way to our understanding of butterflies.

The caterpillars are herbivores that graze on their food plants. The adults play a role in pollination. All stages provide food for predators.

Avoiding enemies is important for survival. The drab, camouflaged wing undersides help this butterfly avoid being seen when at rest. The bold eyespots on adult buckeyes probably serve to startle potential predators long enough for the butterfly to escape.

Although caterpillars incorporate toxins in their bodies, adults, when emerging from the chrysalis, expel the toxins with waste products and thus lose this protection from predators. Because butterflies are vulnerable to predation when their wings are soft, buckeyes’ ability to expel toxins at a predator may be an important defense.

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About Butterflies and Moths in Missouri
Butterflies, skippers, and moths belong to an insect order called the Lepidoptera — the "scale-winged" insects. These living jewels have tiny, overlapping scales that cover their wings like shingles. The scales, whether muted or colorful, seem dusty if they rub off on your fingers. Many butterflies and moths are associated with particular types of food plants, which their caterpillars must eat in order to survive.