Fun Facts about the Monarch Butterfly and Caterpillar

Did you know?

• The monarch larva (caterpillar) molts, or sheds its skin, five times before entering the pupa stage.
• Each stage is called an “instar”. The caterpillar will sometimes eat this shed skin for 4 of the 5 molts.
• The caterpillar is in this stage from 9 to 14 days depending on summer temperatures.
• Male monarch butterflies have a black spot on a vein on each hind wing. Females have no spots on this vein.
• Monarchs use “thermals”, or updrafts of warm air, just like migrating birds do. This allows them to glide as they migrate, helping to conserve energy along their long journey to the over-wintering sites in Mexico.
• What goes in must come out. All that milkweed a caterpillar eats in it’s 10-14 day lifetime moves through it digestive system and must come out. Frass is the name for caterpillar poop. And caterpillars make alot of frass!
• A Monarch caterpillar will gain about 2,700 times its original weight. A large monarch caterpillar can eat an entire milkweed leaf in less than 4 minutes!
• A fifth instar Monarch caterpillar hangs upside down in a ‘J’. It spins a silk button to hang from, rests for about 10-12 hours, and then sheds its skin for the final time. The pupa stops wriggling and the outside skin hardens into a protective covering that will protect the newly forming butterfly inside. Click here to see the “Pupa Dance”.
• Monarch butterflies fly 2,000 miles or more to the cool moist Oyamel fir forests in central Mexico. They do this to escape the coming cold, snowy weather. There they hang out with millions of other Monarchs and wait out the winter. They then start to migrate north by the end of March in search of milkweed to lay their eggs on in the southern parts of the United States.
• Monarch butterflies smell with their antennas! They use their compound eyes to locate flowers and then their antennas to ‘smell’ the nectar and finally they ‘taste’ the flower with the bottoms of their feet! Special receptors on the ends of their feet, called tarsi, ‘taste’ sweet liquids. Yum!