This page shows photos and videos taken of Monarch caterpillars raised inside, and of some found outside in the garden.
Sometimes caterpillars will gnaw at the base of a flower stem in order to partially detach it from the stem, and leaving it there hanging down, as if this would make it easier for them to eat the flowers.
Caterpillars go through five stages of growth or instars, and each time they shed their skin for a bigger one and eat the molt for its nutrients.
When they are ready to turn into a chrysalis, they stop eating and search for a suitable location to pupate, sheltered from predators and the weather.
They then weave a silk pad to hang from. As opposed to spiders that secrete their silk thread from the tip of their abdomen, caterpillars secrete their silk thread from their mouth.
Monarch caterpillars will readily feed on immature seed pods:
SEARCHING FOR A SUITABLE SPOT TO PUPATE
I had two particularly ‘restless’ or fussy caterpillars (nos. 14 and 15 out of 17 raised) that kept crawling for hours before finally settling on a screen I had to arrange especially for them. (I was starting to get concerned they were wasting energy for nothing.)
The caterpillar below on the Swamp milkweed stems, then on the fern leaf, was seemingly unable to find a suitable spot, so I decided to move it into a nearby lilac, where it quickly turned into the ‘J’ phase (see further below).
EXTENDING THEIR BODIES: When exploring around for a suitable spot to pupate, Monarch caterpillars can extend their bodies without support quite a bit (see below photo and video).
The seemingly endless search for a suitable spot to pupate:
THE ‘J’ PHASE
When the silk pad is ready, the caterpillar attaches itself to it from it last proleg pair, and slowly lets go of its 4 other pairs of prolegs, one by one.
It then hangs head down in a ‘J’ shape, a stage which lasts around 10-12 hours before it turns into a chrysalis.
This video (a bit blurry, sorry) captured the moment the caterpillar lets go of its last pair of prolegs to get into the ‘J’ position.
Here’s why it’s crucial for the Monarch caterpillar to attach itself securely to its silk pad:
TOO CLOSE FOR COMFORT
Monarch caterpillars don’t appreciate being touched by another caterpillar, and will lunge at them. Yet they don’t show that reaction when we handle them.
Here’s another video of an ‘altercation’ between Monarch caterpillars:
Not all Monarch caterpillars are created equal in terms of color, as can be seen below. Some have more prominent black stripes and for others it’s the other way around, more prominent white stripes.