Tuesday, February 26, 2013

Monarch Caterpillar shedding it’s skin 2.26.13

The plants in the Butterfly House were getting short on leaves and it needed cleaning.

I removed all the pots….vacuumed the droppings off the bottom and washed the tray the plants sit in….put a Giant Milkweed in the tray and several of the smaller plants that still had leaves and caterpillars.

The caterpillars on the Giant Milkweed that is going back outside had about 15 caterpillars on it. They had to be moved to the new one. I don’t move them unless I see them crawling or eating. When they sit still for a long period of time…they are usually getting ready to shed their skin. They have their hind feet anchored and if moved at this time, they could die. (I found that out the hard way. ) If the skin of the hind feet isn’t anchored they are unable to get out of it and then they die.

This caterpillar was the only one that didn’t move, other than to rock back and forth…a sign it is going to shed.


I picked the leaf and set it on a table where I could watch it. I noticed the skin behind the head was a lighter yellow…the process had started.


In the video you can see it rocking side to side. It does that for awhile. I started filming at 8:06 and it was almost 11:00 before it was completely out. I edited it to keep it shorter.

Once you see it start to ripple it’s body, it is moving the skin to the rear. When I move the leaf, the skin is about half way back and you can see how the old skin is anchored to the leaf. It’s back feet come free about the same time as it is able to knock off the old face. When I turn the leaf again, you can see the pile of shed skin.

They do this about 5 times.  Many climb on a dead branch, the side of the pot or on the screen of the Butterfly House. Outside they could be anywhere. I think they try to be in a spot that doesn’t get a lot of traffic. They are very vulnerable during this time. It seems like they eat for a day…sit for a day…shed skin and eat again. During the summer it takes about 9 days for them to get big and pupate. Once they shed it seems like they double in size in no time at all.

Hope you enjoyed the video….again…no matter how many times I get to watch this…I am still amazed.



  1. I learned something new. I did not know that monarch caterpillars shed their skins. I think I have seen the skins though. Thanks for sharing.


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