Junonia coenia

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Geographic Range

This species occurs in southern Canada east of Saskatchawan, and throughout the United States except for Montana, Idaho, Washington, and western Wyoming. From there it ranges south and east to Bermuda, the Bahamas, Cuba, nearly all of Mexico except southern Baja California. (Scott, 1986)

Habitat

Junonia coenia tends to like more open areas such as fields, parks, pastures, meadows, and coastal dunes. You can also find them along roadsides and in other disturbed, weedy places. They are often near their food plants, and may also feed or drink around mud puddles. (Scott, 1986)

Physical Description

The eggs of Junonia coenia are a dark green.

The larva that hatch from the eggs are nearly black and have two rows of orange-cream spots along the middorsal. There are two lateral rows of cream spots and the larva has many bluish-black spines. The prolegs are orange. The head is black with an orange spot toward the anterior and two short black spines on top, and orange on the top and sides.

Pupa color varies from light color with brownish-orange blotches, to entirely brownish-orange, to nearly black.

The adult stage of the butterfly has brown wings with three eyespots per wing, one on the upper and two on the hindwing. There are characteristic orange bands on the forewing. They have a particularly large eyespot on the hindwing that is reddish to purple. Adult coloration varies, with a form called "rosa," (with red under-hindwings) that appears late in the fall in eastern U.S., and may be a result of short daylength or lower temperatures. (Holland, 1997; Scott, 1986)

  • Range wingspan
    4 to 6 cm
    1.57 to 2.36 in

Development

Female buckeyes lay eggs individually on buds and leaves of host plants. The larvae (caterpillars) emerge and feed and grow on the host plant, molting several times. Larvae transform into pupae, and spend the winter in this stage in the northern part of the range. Metamorphosis is completed in the pupal case, and fully developed adult butterflies emerge. They can take flight after their wings dry. In the southern half of the range, this species may develop and reproduce continually with no diapause or winter dormancy. (Scott, 1986)

Reproduction

Males perch on the ground or low plants and watch for passing females. They pursue any likely object. Females inclined to mate will land, and the male will follow. Courtship behavior is variable. Sometimes they land, fold their wings, and mate. On other occasions females have been observed fluttering their wings after landing. The male responds by hovering over her and fluttering his wings as he lands behind her. The male will then pursue her by nudging her from behind. They will then mate, or if she chooses not to mate, she will flap her wings with a high intensity, spread her wings and lift her abdomen to deny him access, or just fly away. (Scott, 1986)

After mating, female buckeyes lay their eggs on the leaves of host plants that their larvae will eat. In the northern part of the range there may only be one or two generations a year, and it's unlikely that adults can survive the winter. Further south (Florida, Texas, California and beyond), there are adults flying nearly all year.

  • Breeding season
    Year-round in southern range, narrowing to summer in the north.

There is no parental care in this species.

  • Parental Investment
  • no parental involvement

Lifespan/Longevity

Junonia coenia does not live a long time. Adults live about ten days in nature, and about a month in a lab. Larvae and adults may overwinter in warm climates (California lowlands, and regions with similar climate). (Scott, 1986)

Behavior

Flight patterns differ for every buckeye depending upon the region they inhabit. There are many flights throughout the year in Texas, Florida and southern California. Migrations tend to be between June-Oct, becoming common in late summer. Mass migrations are common, and on one of these migrations a population settled in Bermuda. The distance of flights are usually 172 meters for the males and 286 meters for the females. (Scott, 1986)

Food Habits

Adults feed mainly on nectar, and occasionally on mud from the edge of puddles (probably for salts and other minerals).

Caterpillars feed on a wide variety of host plants, nearly all herbaceous (see partial list below). Females may be stimulated to oviposit by the presence of iridoid glycosides (Kluts, 1951, Scott, 1986).

Foods eaten: plantains (Plantago), gerardia, toadflax (Linaria), wild snapdragons (Antirrhinum), false loosestrife (Ludvigia), stonecrop (Sedum). (Kluts, 1951; Scott, 1986)

  • Plant Foods
  • leaves
  • nectar

Ecosystem Roles

Buckeyes, like most butterflies, can be important pollinators.

  • Ecosystem Impact
  • pollinates

Conservation Status

Due to their large abundance, J. coenia is currently not on any endangered species list.

Other Comments

In older texts, buckeyes were known as Precis coenia. However, the binonimal nomenclature has been altered and it is currently referred to as Junonia coenia.

Contributors

Matthew Wund (editor), University of Michigan-Ann Arbor.

Harold Critney (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diapause

a period of time when growth or development is suspended in insects and other invertebrates, it can usually only be ended the appropriate environmental stimulus.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

fertilization

union of egg and spermatozoan

folivore

an animal that mainly eats leaves.

herbivore

An animal that eats mainly plants or parts of plants.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

internal fertilization

fertilization takes place within the female's body

island endemic

animals that live only on an island or set of islands.

metamorphosis

A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.

migratory

makes seasonal movements between breeding and wintering grounds

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nectarivore

an animal that mainly eats nectar from flowers

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

polygynous

having more than one female as a mate at one time

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

semelparous

offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

suburban

living in residential areas on the outskirts of large cities or towns.

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

year-round breeding

breeding takes place throughout the year

References

Holland, W. 1997. The Butterfly Book. New York, NY: Doublebay, Page and Company.

Kluts, A. 1951. A Field Guide to Butterflies of North America East of the Great Plains. Boston, Massachusetts, USA: Houghton Mifflin.

Parcnti, U. 1978. The World of Butterflies and Moths. New York, NY: Putnam.

Sbordoni, V. 1998. Butterflies of the World. Willowdale, Ont.: Firefly Books.

Scott, J. 1986. The Butterflies of North America. Stanford, California, USA: Stanford University Press.