Water Strider/Pond Skater (Photo By Webrunner – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=10424206)

Dear Readers, some of the first animals to appear on my pond in the spring are the pond skaters – members of the true bug family (Hemiptera) that skate along the surface of the water, hunting for anything unfortunate enough to have fallen in. They’ve always fascinated me, but I’ve often wondered how they cope when there’s a thunderstorm. How do tiny, fragile-looking creatures like pond skaters survive when there’s a deluge? Each raindrop weighs more than forty times more than the insect, and you might expect it to be squashed. Enter scientist Andrew Dickinson of the University of Tennessee. He put some water striders (the American equivalent of pond skaters) into an aquarium and bombarded them with water drops. Like you do. And recorded it in slow-motion. Have a look below.

https://www.youtube.com/watch?v=QTgz-egvfgg&t=9s

The insects survive the initial impact by disappearing into the ‘impact crater’ created by the water drop – the crater absorbs most of the force, and then the insect is whooshed (technical term) into the air on the column of water that erupts from the crater. Other insects who don’t get a direct hit may end up being thrown out of the way, or submerged briefly before their hairy legs (which trap air bubbles) enable them to return to the surface. Furthermore, some water striders seemed to sense the water drop coming and somersaulted away backwards before it hit the water. Very impressive.

You can read the whole article here.

However, what happens to insects or other invertebrates when it rains on land? Many animals simply shelter – bees seem to be able to sense that rain is coming and simply stay indoors, while many spiders hide under leaves. But what about insects like mosquitoes, who are found most commonly in humid areas with high rainfall?

One legend was that mosquitoes could dodge between the raindrops, but mechanical engineer David Hu, of the Georgia Institute of Technology at Atlanta, decided to put their flying abilities to the test. Mosquitoes were popped into a box with a mesh roof, and water was sprayed to simulate rain.

Hu found that rather than trying to dodge the raindrops, the mosquitoes completely ignored them, but each blow only deflected them for a fraction of a second before the insect continued on its way.

Next, Hu constructed ‘artificial mosquitoes’ – little pellets that approximated the size and weight of the insects – and pummelled them with artificial rain. He discovered that upon hitting the pellets, the raindrops deformed slightly but weren’t significantly affected – only about 2% of the speed of the raindrop was transferred to the ‘mosquito’, allowing it to continue its flight path with a minimum of disruption.

Hu, being an engineer, thinks that the main use of this discovery could be in the development of teeny tiny flying robots, who would be able to survive a rain shower without deviating from their chosen quest . Personally I find the idea a little worrying, but there we go. And hats off to mosquitoes, who seem to be pretty much invincible. Let’s hope that we don’t kill off all the many, many creatures who rely on them for food, or we really will be in (more) trouble.

You can read the whole article here. And here’s a film showing the research in more detail.

Mosquito on marigold flower (Photo By Abhishek727Abhishek Mishra – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=142114963)