Monarch Butterfly Fund

About us

The life of a monarch begins when a female monarch lays an egg, usually on the underside of a milkweed leaf. The egg hatches after 3-5 days to reveal a very small larva (caterpillar). Over a period of 9-15 days, the larva increases its body mass about 2,000 times as it grows and molts (sheds its skin) five times to allow for the rapid increase in size. The period between each molt is called an instar; monarch larvae undergo five instars, so the largest caterpillars are fifth instar larvae. Each larva then pupates and spends another 9-14 days as a chrysalis or pupa. When fully developed, an adult butterfly emerges from the pupa casing. It pumps fluid from its abdomen into its wings, and in a short time the wings dry and harden. The new monarch then flies to nectar and soon mates. If it is a female it starts laying eggs.