Monarch Butterfly

Habitat
The monarch is a widespread butterfly. In Costa Rica it is common in open habitats, particularly pastures where its Asclepias host plant is abundant.

Range
This species can be found on both slopes of Costa Rica from sea level up to 2,500 m in elevation. It also lives on Cocos Island. Beyond the country’s borders, the monarch ranges and migrates throughout the world, including both of the Americas, the West Indies, the Philippines, Australia, and other regions.

National Parks
Monteverde Cloud Forest Reserve, Santa Elena Reserve, Children’s Eternal Rainforest Reserve, and Cocos Island.

Physical Description
One of the more widely recognized butterflies, the monarch has a rusty-hued orange background color with stark black veins on its wings. The black wing edges have small white spots. Larvae are a yellowish green with black and white striped bands, and a striped head of green and black. The caterpillar becomes a pale green pupa with a ring of tiny gold studs that resemble a slight crown.

Biology and Natural History
This butterfly is famous for its enormous migrations, traveling vast distances across the North American continent, back and forth between southern and northern habitats. In other parts of the world the migrations can go in different directions. In Costa Rica, the local population of monarchs travel between the east and west coasts of the country, and do not intermingle with the populations from the United States or Canada.

The monarch is poisonous. As a caterpillar it drinks nectar from milkweed flowers (Asclepias) which contain toxins that cause unpleasant pain to birds or other predators that try eating the monarch. The monarch retains this toxicity even after it turns from caterpillar to butterfly, and other butterflies that mimic the monarch’s color pattern can also be protected by looking poisonous.

Diet
In Costa Rica the monarch’s host plant is Asclepias curassavica. As an adult, this same flower is a predominant nectar source, but other flowers in the same genus may also provide food for the butterfly.

Height/Weight
A medium-sized species, a monarch’s wing can be 4 to 5 cm wide.

Taxonomy
Order: Lepidoptera
Family: Nymphalidae

Sources
DeVries, Philip J. The Butterflies of Costa Rica and Their Natural History: Papilionidae, Pieridae and Nymphalidae. Princeton, NJ: Princeton University Press, 1987.
Hogue, Charles L. Latin American Insects and Entomology. University of California Press: Berkely and Los Angeles, 1993.

-Amy Strieter, Wildlife Writer