Cecropia Moth Project, Day 55

Cecropia caterpillar cocoon

All four caterpillars have pupated and they are now silking away inside the cocoons (we can hear them working). The cocoons are very hard and the caterpillars will continue to add more layers of silk over the next six weeks. After this six weeks of work we will place the cocoons in the refrigerator to simulate winter for five months.

Cecropia caterpillars cocoons tied to a string

Cecropia Moth Project, Day 51

This past week we started to get worried that something was awry in caterpillar world.  After looking again at the other Cecropia blogs that we've been referencing throughout this process we realized that our caterpillars had long passed the five week mark when they should have started spinning cocoons. Our caterpillars were nearing seven weeks, and we noted that they'd become less active and that their frass size and output had decreased. Our immediate concern was that we'd given them a disease by touching them (you are not supposed to touch the caterpillars without first thoroughly washing your hands, as bacteria is transferred easily to the insects). While we'd generally taken precautions there had also been times when we hadn't.

Our concerns were quickly laid to rest when we returned home yesterday afternoon to find that one of the caterpillars had taken a giant frass, expelling a large amount of water in the process. We'd read that this is what happens before they are getting ready to pupate, as they will be locked away for months unable to empty their bowels. Interesting to note is that the caterpillar was hanging completely vertical from a twig, holding on with only its front (real) legs -- the first time we'd ever seen this behavior. The front legs do not have grippers like the prolegs, so it seemed odd that the caterpillar would be dangling in this way that to us looked rather precarious.

Holy frass!

Red arrows point to front legs, blue arrows point to prolegs

Within an hour the caterpillar had gripped back on entirely and moved to a different location in the habitat. Later last night we found that the caterpillar had started spinning (!) and pulling leaves in around it (we padded the habitat with additional leaves knowing that the caterpillars piece the cocoon together by pulling in leaves). This morning we woke to find a tidy looking albeit half finished cocoon. Exciting.

We imagine that we'll be seeing more frassy messes and cocooning in the next day or so. 

First cocoon

First cocoon, another angle

Cecropia Moth Project, Day 47

5th instar Cecropia caterpillar

The Cecropia caterpillars continue to grow, and they'll likely start spinning cocoons any day now. We are still waiting for the front horns to turn orange as we've seen on other 5th instar Cecropia caterpillars. Perhaps this won't happen. If it doesn't, we'll be curious to know why. Maybe diet?

New habitat arrangement

We changed the habitat once again to accomodate the caterpillars' desire to hang and their eventual need to spin. We drilled holes into a small wooden board and placed the water tubes and additional sticks within those holes. We are keeping the habitat flush with maple leaves. If caterpillars had emotions, I imagine they'd be happy with the new arrangement. They are quite active and eating a lot.