Nitey Nite

Shh! We've just put 850 Regal Fritillary caterpillars to bed for the winter. They are all in the Larva Lounge, our new refrigerator that's just for caterpillar cold storage. What does a Regal Fritillary bed look like?

Fritillary Caterpillars on a Yurt

We start by placing the caterpillars on yurts- bits of corrugated cardboard. The larvae settle down in the grooves of the corrugation.

Toledo Cage Insert.
It's a plastic tube sliced near the top. A thin sheet of organza silk is stretched over the bottom piece, and the top piece reattached with acrylic glue.

The yurts are placed on Toledo cage inserts. These were invented at the Toledo Zoo (Go Mudhens!) as a way of storing caterpillars in a refrigerator without having them dessicate.

Toledo Cage awaiting lid

The Toledo cage is completed by placing the insert, with yourts, inside of a pint canning jar, and adding water to about 1/3 the height of the insert. Another sheet of organza is stretched over the top of the jar, and the lid band screwed down. The idea is to keep the caterpillars in the jar and out of the water, but to keep plenty of water around. Refrigerators dry things out very quickly, and this kills caterpillars.

Over the winter, we'll check the larvae weekly, looking for mold and dessication. If we see mold, everything will go into a fresh, clean setup. If we see dessication, we'll wake the caterpillars up and give them a drink of water before putting them back to bed (see, it's just like trying to get kids to sleep through the night).

Next spring, we'll wake the caterpillars up and rear them on to adulthood. Then we'll release this endangered species onto a site in southwest Cook County to establish a new population.

Regal Fritillaries
Photo: Ron Panzer