After spotting the vermilion orange flash of a Monarch butterfly laying eggs on my milkweed, I kept watch by tying a string on each leaf that had an egg on it. I was surprised, monarch eggs hatch quicker than the black swallowtails. Within a few days I spotted a small hole on one of the leaves. Sure enough, underneath I found an almost microscopic monarch butterfly caterpillar. 

Because I’ve experienced the dilemma of monarch caterpilla cannibalism, I needed to find a better way to raise them this year. I brought one of the monarch caterpillars in on its leaf and using an old water bottle, garden cloth, and a rubber band I created a standalone leaf holder for the small caterpillar. Besides working at keeping the caterpillar separated, the bottle added a benefit; the leaves have stayed pliable and fresh for days.

To create more stem for the leaf to absorb water, I cut up along the edge of the stem, always careful to be aware of where the caterpillar is on the underside, next remove a v-shape portion by cutting away the leaf to form a stabilizing appendage to grip the garden cloth. I could go on with an explanation, but I think the photos tell the story better. 

The caterpillars are thriving. They are now big enough for me to be able to see their spiky anthers.

In the course of adding water to the bottles, one caterpillar fell off on the rug, which is the same color as the caterpillar and even the same texture. I couldn’t find the small cat anywhere. I felt terrible. There was no sense in looking for the fallen caterpillar because I might squash it with my knee or foot while I searched. Instead, I laid a few leaves in the area where I thought it fell. The strategy worked, and today I found the wayward caterpillar on the leaf I laid on the floor. It is safely back on the rearing bottle now.

You can tell, by the holes in the leaves, and the freshness they’ve retained, that the single bottles work much better than leaving all the caterpillars in the bottom of the butterfly cage. Unfortunately, last year that is what I did, and I had seven caterpillars at one time on the bottom of the enclosure, eating the leaves. Overnight, my number was down to one. Yes, caterpillars of the monarch butterflies, although they are beautiful and delicate, are voracious cannibals of each other.

I might run into some trouble when they are big enough to loop themselves from one leaf to another. Maybe the problem will never present itself, but at least I am on the lookout for it. 

I am grateful that I have a whole garden bed filled with milkweed. I checked some of the wild areas and the milkweed is in horrible condition. I found no caterpillars, only aphids spiders, ants and other bugs that prey on the monarch caterpillars. The leaves were leathery and dry from all the hot weather in our area. I have the advantage with my garden bed since I keep it well watered and stay on pest alert at all times.

This has been longer than my normal posts, but I wanted to share how to keep the leaves fresh, and the caterpillars away from each other. One note, they do like to be shaded. I keep them shielded from the Sun with dish towels over the sides. So far none have attempted to reach the other leaves. They are thriving and growing. I’m looking forward to watching the process over the next few weeks.