Pupating In A Flash

The web leads here, the web leads there – today the web took me to butterflies, pupae, and ….. word of the day – Cremaster.

I follow HoneyBeeSuite for information on honeybees.

What I found was not bees but butterflies – and the change from caterpillar to pupa.

The author of the HoneyBeeSuite is named Rusty, and she is a beekeeper living in western Washington. She is also a director of the Native Bee Conservancy, a non-profit organization dedicated to education about wild pollinators.

She also writes a monthly column for Bee Craft, the journal of the British Beekeepers Association.

Her blog is a terrific resource. I came across it while maintaining the page where I curate articles about colony collapse disorder in honeybees.

The thing that grabbed me about Rusty’s article was that she mentions that the transition from caterpillar to pupa happens in a flash.

One of her readers had submitted a photo showing the transition part way through.

Well that looked interesting and the idea of something as radical as this transformation happening in a flash, got me hunting around the web for more information.

I found a great series of slides at OneBecomesUs (site now defunct) and the description of how the caterpillar does the trick of holding on to the silk anchor that fastens it safely to the branch from which it is hanging while it is transforming itself, is quite something.

As the author explains, the caterpillar emerges from its old dead skin and the new chrysalis (the pupal stage of butterflies) attaches itself to the silk anchor by a hook called a cremaster .

However, there’s a problem. It can’t jettison its old skin because its hind claspers are also attached to the silk anchor.

Somehow, it has to extract and reinsert the cremaster into the silk anchor while, at the same time, using the now dead caterpillar clasper as an anchor. What the pupa does is to extract the cremaster from the anchor and immediately twist and turns to reinsert it firmly into the silk. Then the clasper lets go and the dead skin falls away.

It reminds me of a climber high on a rock face, switching ropes to anchor himself while in the act of falling.