Can you imagine your life’s work (and your children’s… and your children’s children) is to travel up and down the United States? This is the life of the monarch butterfly (Danaus plexippus)! These polka-dotted, stained glass-winged butterflies are all about life cycles since that is how they get around.
Monarch butterflies start off in the south during spring time. Eggs are laid on milkweed and the metamorphosis begins! The eggs hatch as larvae and start chowing down on milkweed, their sole source of food. As the larvae continue feeding on milkweed, they turn into fat white, yellow, and black striped caterpillars. The third stage of metamorphosis is when the caterpillar spins a gold speckled, jade green chrysalis around itself and becomes a pupa. After 10-14 days, a fully formed butterfly emerges from the chrysalis and feeds on the nectar of flowers. This life cycle occurs 4 times from spring to autumn. The first 3 cycles last 4 weeks and progressively travel north during their life cycle.
The last cycle of the season is called the super generation. These butterflies live up to 8 months, 8 times longer than the previous 3 generations. The butterflies of the super generation start the migration back down to the southern states in mid-August and travel more than 3,000 miles to their destination. Once they reach their destination, they hibernate through the winter in groves of eucalyptus trees. When spring arrives, the monarch start the whole process all over again.
Monarch butterflies are affected by climate change as rising temperatures pushes their habitat range further north, which makes the migration down south longer. The loss of milkweed and nectar producing flowering plants along their migration route can also contribute to the alarmingly decreasing number of monarchs.
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