Monarchs are the panda bears of the insect world–everyone loves, them right?
Right. Except if you’re in the peculiar position of trying to grow monarch fodder for customers who don’t want their plants pre-eaten.
As we are at Zealandia.
We’re wholesale plant growers. We sell plants to big box stores like Mitre 10 and Bunnings (the NZ equivalent of Lowes and Home Depot). Customers buy plants from these big stores to feed their own caterpillars, and don’t want to be buying more hungry mouths to feed with their plants.
We still love monarchs; everyone does. But they present us with an interesting puzzle.
The roofs of our greenhouses open. The wind and direct sun help keep the plants strong and stocky–but they also let in all manner of insects, including mama monarchs. One of my jobs and the nursery is pest control, and when monarch caterpillars are eating our asclepias plants (what monarchs eat in NZ instead of milkweed) before we can sell them, that’s a problem.
I think we might try growing some big aslepias in the greenhouse, with the thought that mama monarchs might choose the biggest plants around on which to lay eggs, and leave our small ones alone. Hey, it’s worth a try.

In the mean time, I got to bring home a big tray of caterpillar-laden plants. We’ve distributed the gems to school and to neighbors, and planted a few plants in our garden in the attempt to grow some monarch food to feed the ravenous hordes later in the summer.

“We have a whole life cycle!” Milo exclaimed, delighted. Hurray for the life cycle poster-child. Every kid starts their entomology with these flashy specimens. (apologies for the out-of-focus white speck on the leaf–that’s an egg)

Eating and pooping makes the caterpillar grow, and complicated hormones govern each molting of the skin.

The caterpillar chooses a nice leaf to attach its bum to with super strong silk. It curls up in a J and starts stewing in hormonal juice, forming a chrysalis skin under the old stripey one. Soon the skin at the back of its neck splits open and the pupae wiggles and shrugs until the dry husk scootches to its silk-glue end.

I have yet to actually see this shrugging off of the old skin in person. You-tube is amazing. After much twisting and turning, the pupae hardens and all motion stops. Yet another hormone-mediated change is taking place.
We don’t have any adult butterflies hatched yet, but if we catch any drying their wings, we’ll have to put up a picture.
I loved this post, Molly! Actually, I love all of your posts, but this one was special. The picture of Milo behind the plant with the caterpillar is precious!
Ha ha Monarchs as pests is a new perspective for me! do let us know how your control works but I think I once heard that momma monarchs choose younger plants because they are more palatable for the just hatched caterpillars. good luck!