Today’s Mystery – Bamboo Twist

Bamboo Twist
The mysterious twisted bamboo leaf

How did this bamboo leaf (right) get tied up so neatly?

I know of several leaf-rolling insects and spiders; There is a range of caterpillars that roll up leaves as shelters to pupate in, crickets and spiders that hide inside rolled-up leaves, weaver ants that use their larvae’s silk to assemble their nests from whole bunches of leaves, and the amazingly crafty leaf-roller weevil.

But even the strength and dexterity of that weevil doesn’t seem enough for what would be necessary to achieve this sophisticated package that I found on a bamboo bush in the Ecogarden. This leaf (and a couple more on the same bush) looks like it was rolled up tightly, then folded while using a narrow band – split from the edge of the leaf – to lock the fold in place.

What – or who – could possibly have done that? Even if (quite inexplicably) a human had a go at foliage modification, I would be quite impressed with their skill! Or is this the result of a mishap that occurred while the leaf was still growing, before it unfurled? But what would have caused that, repeatedly and on different parts of the bush?

Can anyone solve this mystery?

Update 30 Jan:

What I didn’t mention above is that I did remove the leaf and open it up, to see what’s inside. But all I found was some detritus that had accumulated at the tip.

Having revisited the bamboo bush to investigate further, I now think the best explanation for this phenomenon is that something or someone folded the leaf while it was still rolled up. Here’s why:

This is all I found when I unrolled the leaf. If something had used this as a shelter, I would have expected more.
I attempted to recreate the phenomenon myself, manually rolling up a leaf, splitting off a narrow band at the edge and locking in the fold. I only succeeded partially.
A number of leaves on the same bush show evidence that they were folded while still rolled up, but they eventually unfurled.
This is a leaf rolled by a spider (I suspect). Obviously tied together from the outside, and probably containing eggs deposited on the inside (although I didn’t check that).
A similar leaf, partially opened and revealing the baby spiders inside (I think).
A spider using a leaf as shelter and hiding place.
Another spider, feasting on a fly while keeping one leg on the thread to her web, in case another fly might get caught…

One Comment Add yours

  1. Danny says:

    fantastic last shot, fascinating observations and fabulous investigative work Andy! Apparently, leaf tying and folding are common habits among caterpilllars as a defence against predation. Maybe they had a hand (perhaps in part) in what you saw… What say you Watson? Watttt-sonnn! where’s that bloke gone off to now?

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