After munching their way through caterpillar life, it’s time for the magic of becoming a butterfly to happen in the chrysalis (the pupal stage). So how does the monarch caterpillar get inside the chrysalis? Let’s take a look at this major transformation stage in the monarch-friendly garden.
Preparing to Form a Chrysalis
When a mature monarch caterpillar is ready to pupate, it will often journey away from the swan plants (or climb if enclosed) and look for a suitable place to transition.
If possible, it’s better not to disturb the caterpillar at this stage or to try to force them into a preferred pupating position. Time and energy are ticking.
When ready, the monarch caterpillar attaches a little wad of silk at its chosen location, spun from its head. The caterpillar then fastens onto this silk and dangles upside-down in a distinctive J shape while preparing to pupate.
The J stage is temperature dependant, and can range from approximately 8-36 hours. If you’re hoping to see a caterpillar pupate, watch for a limpening and drooping of the outer features like the antennae on your dangling caterpillars. Despite our many monarch caterpillars, I’ve rarely had the opportunity to see the full process. If you’re keen, it’s worth trying. Watching it happen is pretty amazing, if you can catch it!
Safety First!
I couldn’t get a photo of the silk pad for the cheeky melon leaf caterpillar pictured elsewhere in this post without disturbing the plant. The (different) caterpillar pictured above decided to dangle on a swan plant seed pod. Crazy cats! But it does give a nice clear view of the silk as it prepares itself for transformation.
It wasn’t worth risking the safety of the melon caterpillar just for a photo. It’s very important that caterpillars not be moved or otherwise disturbed when they’re at this stage, if at all possible. Caterpillars who have gone into their dangling J in preparation for pupation might not be able to reattach elsewhere after a disturbance. This would, unfortunately, lead to an early death instead of their ongoing transformation.
Transforming from Caterpillar to Chrysalis
Once the caterpillar is ready to pupate, the actually transformation from dangling J to chrysalis occurs quite quickly. The caterpillar splits and sheds its skin one final time, starting from the head and splitting progressing down the back of the body, revealing the formed chrysalis beneath. Almost like it’s being unzipped from the skin. It then does a wiggly little dance whilst dangling from its cremaster to shake free of the molted skin.
The newly formed chrysalis is soft and bumpy, with a pale greenish yellow colouration. Not what were expecting? Don’t panic! That’s normal immediately after transformation.
The new chrysalis gradually tightens into a smooth and more familiar form. Then the outer casing slowly dries and hardens, taking on a slightly darker green colour. Look at the different in the appearance of the same freshly formed chrysalis a few hours later!
Monarch Chrysalis Care and Support
Monarch Chrysalis Care
Chrysalides require little care. There is no eating or pooping during this development stage. Shelter from extreme temperatures (hot or cold) can help ensure the chrysalis remains viable. If conditions are really hot and dry, it can be helpful to periodically lightly mist them to help maintain a natural moisture level. If the chrysalis becomes too dry and hard, it can become difficult for the butterfly to safely eclose when the time comes.
Moving Monarch Chrysalides
A freshly exposed chrysalis, like the bumpy one above, is very soft and fragile until it tightens into itself, dries, and hardens. If possible, allow this process to happen before any movements. Monarch Butterfly Garden has good tips and photos for moving J caterpillars and chrysalides if you find yourself in urgent need. But only if it’s urgent.
I have a DIY “chrysalis palace” made from scrap plywood and mesh shade cloth to relocate or rescue fallen chrysalides. I rehang them securely below the mesh with dental floss or tape if the chrysalis is still on a leaf or branch. The structure is cheap, portable, easily cleaned, and works well. It feels great to see a rescue safely depart as a butterfly.
Sometimes a rescue is unavoidable, but I’ve managed to avoid many chrysalis movements by temporarily relocating objects to safer positions or by temporarily propping things up to create free space around low-hanging or crowded chrysalides.
Sometimes, the chrysalis is in a tricky position on a leaf that can’t be moved or propped. For those, if the leaf is still healthy and secure, I wait until a day or two before the butterfly will come out before moving the entire leaf with chrysalis still attached. The leaf can be taped securely in a safer position for opening, and waiting helps to ensure the leaf will hold together until the butterfly safely departs. If waiting isn’t possible or the leaf is compromised, a full rescue and rehang with floss may be safer and more secure.
Monarch Development in Chrysalis
Similar to the caterpillar stage, the monarch’s pupal stage in the chrysalis lasts approximately two weeks, depending on conditions.
If you’ve not seen a chrysalis before, they might look alarming small to eventually hold an entire butterfly, but they can (more on that in our next post!). The butterfly transformation occurs inside the chrysalis casing. It does not grow or expand. Tight quarters, indeed!
When the transformation (metamorphosis) is nearing completion, the appearance of the chrysalis will start to darken and the butterfly inside becomes incrementally more visible until it can be clearly seen inside a now almost transparent casing. Butterfly time is near!
