Monarch Butterfly (Danaus plexippus)
The distinctive Monarch Butterfly has bright orange wings with wide black borders and black veins; its hindwing has a patch of scent scales and white spots on its borders and apex. The typical wing span is 33/8 to 4 7/8 inches (8.6-12.4 cm).
The Monarch caterpillar has alternating yellow, white and black stripes.
The Monarch Butterfly prefers open habitats including fields, gardens, meadows, weedy areas, marshes, and roadsides.
The Monarch caterpillar feeds solely on Milkweeds in the genus Asclepias. The most commonly grown in Bermuda are the red and yellow flowered Asclepias currassavica and the white flowered Asclepias physocarpa. The Monarch butterfly feeds on nectar from Milkweeds and other flowers.
Most milkweeds contain cardiac glycosides which are stored in the bodies of both the caterpillar and adult. These poisons are distasteful and emetic to birds and other vertebrate predators. After tasting a Monarch, a predator might associate the bright warning colors of the adult or caterpillar with an unpleasant meal, and avoid Monarchs in the future.
Adults warm up by basking with their wings open and toward the sun. Females lay eggs singly under the leaves of the host plant (Milkweed). Caterpillars eat leaves and flowers of the Milkweed.
Bermuda has both a resident and migrant Monarch population. The local population was noted in 1847 when a population was seen breeding all year.
The migratory population is observed occasionally. These adults make massive migrations from August-October, flying thousands of miles south to hibernate along the California coast and in central Mexico. A few overwinter along the Gulf coast or south Atlantic coast. Along the way, Monarchs stop to feed on flower nectar and to roost together at night. At the Mexico wintering sites, butterflies roost in trees and form huge aggregations that may have millions of individuals. During the winter the butterflies may take moisture and flower nectar during warm days. Most have mated before they leave for the north in the spring, and females lay eggs along the way.
To attract Monarch butterflies to your garden plant the yellow and red-flowered Bloodflower (Asclepias currassavica), yellow-flowered Butterfly Milkweed(Asclepias tuberosa) and the white-flowered Balloonplant (Asclepias physocarpa).