Monarchs leave their Mexican roosts in the second week of March
For those of us in the South, Monarchs are already creating the 1st generation of the year, moving north from Mexico and laying eggs on milkweed plants. These Monarchs have had an incredible journey in their migration south in the fall, and now they work to create the generation that will recolonize the southern United States.
The Monarchs develop from egg to adult in about 30 days:
- Eggs hatch in about 4 days. Females lay one egg on a plant; in their lifetime they will lay 100-300 eggs.
- Caterpillars go through five instars in about 14 days. When they first hatch, caterpillars eat the egg shell for nourishment. Similarly, they eat shed skin after every molt.
- Chrysalis stage is about 14 days
The overwintering generation lives about eight months due to a biologic change that stops reproductive behavior during their migration south. The summer generations of the butterfly live only three to five weeks.