While running one morning, I passed a well developed patch of milkweed, and happened to notice a monarch larva chomping away on a leaf. Later I returned, and after doing a quick survey of the patch, I grabbed two nearly full grown larvae, and two middle sized plants for them to eat. Based on the size of the larvae, about 4.5 centimeters, I figured they would pupate in a day or two.
Sure enough, two days later, after dropping much poop on our counter and then taking off up the walls in search of a spot to spin a silken pad to hang from, we found them. One was on a beam of our timber framed house, and the other was on the window screen. Sadly the one on the screen was later attacked by a cat and died…or rather was gutted. Oops. The other continued throughout that day and the following to spin his pad, and then to slowly let go and enter the “J” stage. That evening, I returned home to find a still squirming green mass. The chrysalis was fully formed by the time it got dark. A couple weeks later I can see some faint wing patterns of the developing adult.