At many of our outreach events we run a cocoon-opening activity, where we carefully explore the structure and function of a cecropia moth cocoon, and reveal the living, wiggling, pupa within. This process does not harm the animal and we store the exposed pupa in a refrigerator and let it eclose as normal each spring. I plan to make a detailed video on how to do a cocoon-opening of your own, for those teachers who would like to take their classroom metamorphosis projects to the next level.
At our recent "Seed Celebration" program in Alstead, NH, we opened a few wild-found cecropia cocoons. We always know what to expect when opening a captive-reared cocoon - but those found in the wild, more often than not, contain some pretty gnarly surprises. In the past we have found mummified, blackened caterpillars, dozens of ichneumon wasp pupa, and the pupal casings of flies. But Saturday was the first time that we opened one in public to actually find dozens of live parasitoid fly maggots in the process of emerging from an oozing pupa!
The watching crowd reacted with the expected repulsed expressions, quickly followed by academic interest, and than lasting fascination. Some visitors came back again and again to witness how the maggots changed over the course of the day, their skin hardening into dark casings, as they started their own metamorphic journey towards becoming adult flies.
The unexpected always leads to the most memorable and powerful learning experiences at our programs, and the lives of these creatures are ripe with unexpected moments!