Remember that large collection of butterfly eggs that I found almost 2 weeks ago? They’ve been eating, pooping, and growing non-stop ever since.
For some reason it seems that some grow faster than others. I generally keep the very little ones in a small plastic container with their food, as it helps to keep them from wandering off. But once they get big enough (third instar if we’re being technical), I transfer them to a larger mesh enclosure where I can provide more food, and where they can eventually pupate.
About half of the growing caterpillars outpaced their siblings, and so I transferred them to the larger enclosure first. The rest went into a second enclosure a few days later. Now that first group has grown to the point where they are ready to pupate.
When they’re ready, they stop eating, purge any undigested food from their stomachs, and search for a place to attach themselves to transition to a chrysalis. In the wild they can travel pretty far – when I used to let them grow outdoors, I’ve found their chrysalises attached to plants over 25 feet away. To get to those plants they would have had to crawl down the pot they were in, up a two-foot tall stone wall, and then across the garden to the plant.
Being in an enclosure limits their ability to find an attachment site. Sometimes they climb the enclosure itself and attach to either the sides or the top (as Lazarus did), but that’s not ideal, as it makes it hard for me to attend to the others without disturbing them. So I create what I call a Pupation Station.
They are pretty simple: I find a branch with a Y-shape to provide a stable base, cut sections of branch at a slight angle, and then glue them to the base. Most of the time the wandering caterpillars find it, and choose to transition there. Here is a photo from last year’s crop of caterpillars, where 5 of them attached themselves to the branches:
So as I mentioned, the first group has already begun the pupation process. Two of them have purged, and have attached themselves to the ceiling of the enclosure. The rest are looking pretty pudgy, and I suspect that they will soon join them.
I took the above photo during a feeding/cleaning session. I remove the bundle of parsley and/or rue from the container of water, and separate the stalks with caterpillars from the rest, which is discarded. I take a bunch of fresh parsley, add the stalks with the caterpillars to it, and tie the base with a rubber band. Meanwhile I empty the glass that holds the water, as it is pretty gross from all the caterpillar poop that drops into it. I’ve started adding some round glass pieces to help prevent the caterpillars from drowning, so those have to be washed too. Then everything is carefully re-assembled and placed back into the enclosure.
Speaking of not drowning, I noticed this morning in the enclosure for the slower-growing caterpillars that one of them was partly submerged.
It looks like it had fallen down from the parsley leaves into the water, but since the glass pieces are there, it was able to crawl back up the stems to continue feeding. It made me very happy to know that I had learned from the bad experience of the past, and that adding those pieces saved a caterpillar from drowning.