Most recently reviewed by: Molly Keck & Tyler Mays (2021)
Common Name(s): Monarch Butterfly
The monarch butterfly, Danaus plexippus (L.), is one of the most commonly recognized and discussed insects in North America. Eggs of the monarch butterfly are laid singly on host plants. Eggs are round with a pointed tip and are a light green color. Upon hatch, a small, white caterpillar with a black head emerges to begin feeding on the host. As caterpillars develop, the body develops black, yellow, and white bands in addition to black tails that protrude from the front and hind ends of the caterpillar.
Pupae are encased in a green chrysalis with a line of small, golden dots around the perimeter. Pupae can be found dangling from the underside of plant tissues and human-made objects, away from the host plant. The bodies of monarch butterflies are black with white dots. The butterfly’s large, orange wings have black veins and white dots around the wing perimeters and tips.
Another butterfly, the viceroy (Limenitis archippus (Cramer)), is commonly mistaken for the monarch butterfly. The viceroy, however, can be distinguished from the monarch butterfly by the veins that occur on the hindwing. Viceroy butterfly hind wings have a vein that crosses other veins on the hind wing. When viceroy wings are held apart from the body, this characteristic vein forms a “W” shaped appearance. Monarch butterfly hind wings lack this particular vein distinguishing them from viceroy butterflies.
Origin and Distribution
Monarch butterflies are found across North America, much of South America, Australia, and some Pacific islands. Monarch butterfly populations occurring outside of North America and South America are not native to those regions.
Monarch butterflies migrate from overwintering locations, the largest of which is in Mexico, to more temperate regions that can be thousands of miles from the overwintering areas. Depending on the temperate region, multiple generations of monarch butterflies can be seen prior to the fall migration to overwintering sites. Monarch butterflies exist year-round in the tropic regions they inhabit.
The monarch butterfly’s annual spring and summer migration from its overwintering sites to temperate sites overlaps with most of Texas, though the majority will fly through central Texas before spreading eastward and westward. In the fall, monarch butterflies will begin their trek from northern locations across the United States and Canada to their overwintering sites in Mexico. As they move southward, the majority of these butterflies will converge in north central Texas and continue their flight south into Mexico.
Habitat & Hosts
Hosts for the caterpillar include milkweed (Asclepias) and a few other plant genera from the family Asclepiadaceae. Butterflies feed on nectar from flowering plants.
The monarch butterfly, like all insects in the order Lepidoptera (moths, butterflies, and skippers), follows a complete life cycle: egg, larva (caterpillars), pupa, and adult. After mating, females lay 100-300 eggs singly on a host plant. After the egg hatches, a larva emerges and feeds on the egg case which contains valuable nutrients. The larva then feeds on the milkweed (Asclepias) or other milkweed plants known as swallow-worts (Cynanchum) to obtain nutrients and chemical defenses that may protect it against predators. Larvae that feed on swallow-worts, however, fail to develop into pupae. Larvae that fed on Asclepias milkweeds go through a series of four molts over the course of 10-14 days before leaving the host plant to start the pupation process. Pupae can be found hanging from other plants or human-made structures. After another 10-14 days, the monarch butterfly will emerge.
ManagementIf you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.
Management of monarch butterflies is not recommended as they are considered beneficial pollinators. Monarch butterflies are not considered a nuisance or pest species. If you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, then contact your local extension for management options.
The Monarch Butterfly in North America. United States Forest Service. Available here.
Monarch Butterfly. University of Florida’s Department of Entomology & Nematology’s Featured Creatures. http://entnemdept.ufl.edu/creatures/bfly/monarch.htm