24 Aug Monarch Butterfly Life Cycle with Photos
Hi Susie….I planted milkweed and got beautiful yellow and black caterpillars. Now they’re gone. I was expecting cocoons. Any idea what happened?
Monarch butterflies start as a tiny white egg laid on milkweed by the female monarch.
The egg hatches in about 2 to 4 days: 
The caterpillar is smaller than a piece of white rice when born and will eat milkweed for 2 weeks, growing 2500 times bigger in that time and eating about 32 leaves! 
Once about 2 weeks old and full grown, it will crawl OFF the milkweed to make a chrysalis (moths spin cocoons, butterflies make a chrysalis) some place else. Nature makes them know to make a chrysalis somewhere else where another caterpillar won’t eat the leaf out from under it! They are caterpillars for 2 weeks, go off the plant to make a chrysalis, in the chrysalis for 2 weeks, then emerge (eclose) as a beautiful butterfly! More at https://vanderlip.com/monarch-butterfly-speaker-blog/
Chrysalis looks like this: 
They make their chrysalis under leaves, ledges, UNDER things to be protected so crouch down and look around!
In 2 weeks, when they are ready to emerge, the chrysalis thins and you can see the orange and black butterfly inside. The day the butterfly will eclose (emerge), it looks like this: 
After emerging from the chrysalis, the butterfly must hang upside down for a minimum of 2 hours for the wings to fill and harden before it can fly. 
Then they live 3 to 6 weeks, drinking nectar from lots of different plants, mating, laying eggs. Until early Nov. Those newborns migrate and hibernate/overwinter through the winter months. Overwintering in Pismo Beach, they don’t fly, eat or mate. They roost in large numbers to keep warm: 
VERY IMPORTANT: Sound like you might have tropical milkweed from South America. It is lovely and caterpillars love it, BUT (a very big BUT), they cause health problems for monarchs if we don’t prune it. It is advised to plant NATIVE MILKWEED for your state if at all possible. Picture of Tropical Milkweed here:
vs Native milkweed. Here is just one type of native California milkweed. There are different varieties of native milkweed for every state:
If so, along the west coast, it is CRITICAL to prune it back right after Halloween or it accumulates a microscopic parasite O.e. that will eventually kill all your butterflies. Read: https://vanderlip.com/blog/2019/08/01/pruning-tropical-milkweed-in-the-fall-imperative-for-monarch-butterfly-health/
To learn all about monarch butterfly life cycle in story and pics and share a beautiful book and movie with children, check out my book and DVD: The Story of Chester, the Monarch Caterpillar/Larva at www.storyofchester.com