Monarch Butterfly
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Scientific Name:
Danaus plexippus Native
Description
Perhaps the most familiar butterfly in North America. Wingspan of 3.5 to 4 inches. Wings are predominantly orange with bold black veination and black tips with rows of white spots along the trailing edges and distal forewings. Caterpillars have stripes of yellow, black, and white with two long, antennae-like projections at the front and rear.
Range and Habitat
Southern Canada through northern South America. Can be found in many different habitat types from forests to agricultural fields to urban centers, as long as wild flowers are available for feeding adults and native milkweeds are available as host plants.
Behavior
Monarch migration is one of the greatest spectacles in the animal kingdom. In the fall, monarchs east of the Rocky Mountains migrate south to Mexico (and Florida); monarchs west of the Rocky Mountains migrate to southern California and Mexico. During the fall migration, dozens of monarchs may feed upon wildflowers along the Louisiana coast at once, which is quite a sight for nature lovers! But the real spectacle is the overwintering sites in Mexico, which may hold tens of millions of monarchs. Upon their return in spring, female monarchs search for native milkweeds to lay their eggs (up to a thousand or more). However, exotic milkweeds, milkweeds treated with pesticides, and nonnative plants that seem to copy milkweeds will occasionally lead to egg deposition on a dead-end host (leading to complete reproductive failure). Because monarchs live less than a year, it may take five generations of monarchs (mating, laying eggs, and developing from caterpillars) to complete a full cycle of migration!
Population Status
Ranked globally as G4 (apparently secure but may be rare in parts of its range); ranked as S4 (apparently secure) in Louisiana. Still quite common, with a global population estimate of 200 to 300 million. However, drastic declines and dramatically fluctuating abundance in overwintering populations are alarming. Main threats include loss of host plants (including switch from native milkweeds to exotic species), overuse of pesticides and herbicides, loss of migratory stopover and overwintering sites.
More Information/References