Egg (3 - 4 days)
Eggs are laid on milkweed leaves and after 3–5 days the caterpillar hatches.
Larva (caterpillar 10 - 14 days)
It is during this stage that Monarchs do all of their growing. They begin life by eating their eggshell, and then move on to the plant on which they were laid.
When the caterpillar has become too large for its skin, it molts, or sheds its skin. At first, the new skin is very soft, and provides little support or protection. The new skin soon hardens and molds itself to the caterpillar, which often eats the shed skin before starting in anew on plant food! The intervals between molts are called instars. Monarchs go through five instars (see photo). Approximate length of body at each stage: 1st instar, 2-6mm; 2nd instar, 6-9mm; 3rd instar, 10-14mm; 4th instar, 13-25mm; 5th instar, 25-45mm.
Pupa (chrysalis)
Over a period of 10 to 14 days, the caterpillar undergoes five instars, the period of time between each molt, after which it will pupate and spend 9 to 14 days as a chrysalis (pupa).
Life Cycle of the Monarch Butterfly
The monarch, as with all butterflies and moths, undergoes complete metamorphosis comprised of four stages: egg, larva (caterpillar), pupa (chrysalis), and adult. This cycle is completed in approximately 30 days.
When fully developed, the adult butterfly will emerge from the pupal case, pump fluid from its body into its wings, and fly off to search for nectar, mate, and (if female) lay its own eggs. In the summer, adults live 2–6 weeks. Migrating monarchs live all winter, approximately 6–9 months. .
Adult
