5 June 2012

How Insects Can Fly In Rain

Do you think that was summer? The rain seems to have come back, and it’s colder. The garden is struggling on but the few seedlings and young plants I’ve brought in seem reluctant to grow. They are like people waiting at a bus stop in the rain. As soon as the bus – sunshine – comes they will be off, but until then they’re shuffling their feet and playing with their I Phones.

It’s noticeable that when the sun does appear the garden is suddenly full of insects again. I wonder where they go and how they survive when the conditions are bad. Do they hide away in dark crevasses or under leaves and spend the time muttering to themselves about British weather? Being cold blooded the air temperature must have something to do with it, in that they simply can’t move until it warms up again. And the rain itself must be a factor. It must be impossible to fly while it’s raining when each rain drop is the same size as you. Just imagine walking around while trying to dodge huge six foot wide blobs of water. It would be like a scene from The Prisoner. And water is heavy stuff; those blobs could knock you out if they fell on you.

There is no wonder insects don’t venture out when it’s raining ... or is there?

Some American scientists have been looking at how mosquitoes survive the impact of raindrops which are up to fifty times heavier than they are. Slowing down the collision using high speed filming techniques reveals not a violent struggle but an elegant dance. As both mosquito and raindrop fall through the air they join together and continue to fall some distance before the hairs on the insect’s body repels the water and they separate to continue on their own paths. One of the researchers, a Dr Hu (say his name out loud – it’s funny) compared what happens to the principle of non-resistance which many Eastern philosophies advocate.

"There is a philosophy that if you don't resist the force of your opponent, you won't feel it," he explained.

"That's why they don't feel the force; they simply join the drop, become one item and travel together."

I like this conclusion from the report abstract:

Our findings demonstrate that small fliers are robust to in-flight perturbations.

So here’s the life lesson we can learn from mosquitoes:

To avoid perturbations go with the flow.

Main article from BBC Nature