Sunday, 20 May 2012

The Caterpillar Post

I promised you caterpillars, so caterpillars you shall have.
 Last month we started Ellie’s first proper project –she has an exercise book and everything- on worms and butterflies, taking in a few other arthropods on the way.
 So far it’s been a lot of fun.
We started off with an old favourite: the worm hotel.
This noble edifice, named The Pancake Breakfast Bed Hotel by Ellie, was constructed in a big plastic jar with layers of soil, sand, and kaolin clay, then we introduced the worms, kept the whole thing dark, moist, and supplied with occasional greenery and waited.
 At the end of three weeks we removed the hotel from the darkness to reveal, not much of anything.
 We eventually found one worm track heading from the top of the jar towards the bottom (Ellie’s theory: “perhaps the worm was going for a little rest at the bottom where it’s quiet”) and learned an important lesson: when making a worm hotel use a smaller jar, our worms had spent their time digging merrily around in the middle of the hotel where there was plenty of room to spread out with bumping into a wall.
So, no worm trails for us, but we still had a lot of fun building the hotel, maintaining it, and talking about worms, what they do, why they’re good for the garden, what eats them, and just about anything else a hermatologist* could dream of.
 Worms down, we took a brief trip into the realm of bees, then on to the caterpillars!
Our caterpillars are Painted Ladies and they arrived, not in eggs as you might expect but by Royal Mail (leading our postman to remark that it’s a little early in the season for them, turns out he’s a lepidopterist**).
They are currently living in a jar on the mantelpiece, eating the caterpillar-food provided and growing at a ridiculous rate.
Ellie checks them every morning and evening, and any other time she thinks they might have grown, and so far they have always proven to be bigger than the last time she checked.

 Today, however, was particularly exciting: they haven’t started making chrysalides (though there’s quite a lot of silk in the jar now) but they have reached an important caterpillar milestone.
Their heads have fallen off!
Fortunately I was expecting this (thanks to Kate for the warning) and was able to look it up in advance.
It seems that caterpillars routinely lose their heads as part of their moulting process: as they grow bigger the old head becomes too small for the new body, so it drops off.
Fortunately by this time there is a new head waiting behind the old one ready to take over, I bet male praying mantises wish they could learn that trick!
 So the jar looks a little gruesome this morning but we’re not worried, we’ll keep on checking every day and soon we should see the first chrysalis.

* Someone who studies worms.
** Someone who studies butterflies, but you already knew that one.
A rather sinister caterpillar, as made by Ellie.

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