Water Striders: Vampires of the Arthropod World

You thought “vampire” should’ve been reserved for mosquitoes, right? Nope, those shall henceforth just be referred to as “dragonfly lunch” until I decide to give them their own post someday – if I ever do a mosquito post. They’re certainly not the most lovable arthropods.

I don’t know what I thought water striders were, but I didn’t think they were insects. They always seemed so spidery to me, but I still didn’t know where to categorize them because I thought they had four legs. Turns out they have six. I really need to start wearing my glasses like a responsible adult.

These mysterious insects have always fascinated me, gliding about like summertime ice skaters on the streams and ponds of my childhood. I was only ever lucky enough to catch one once, which was an interesting experience to say the least – while water striders look poised and peaceful most of the time, they instantly become very frantic and unnatural-looking when lifted off the water. The unfortunate strider that I happened to catch that day went from calm and collected drifting by my legs in the stream to instantly scrabbling around in my little toy net like a deranged spider.

Disturbed by its sudden change in temperament (but I mean, who could blame it, I had just hoisted it into the air out of nowhere, and if you’re a water strider not on the water that means you’re getting eaten most of the time), I immediately dropped him back in the water and never tried to catch a water strider again – except on camera so I could put a picture in this post.

You’re probably wondering why I’ve decided to call these guys “vampires” since they don’t suck human blood. In fact, they don’t really like blood at all – just the innards of other insects.

Imagine for a moment that you’re a moth and you’ve fallen into a pond. You’re in quite the tragic situation – you’re not sinking, but you’re unable to free yourself from the surface tension of the water. You’re a sitting duck for everything swimming below you, everything flying above you, and even predators watching from the shoreline. Oh, wait! An insect buddy is swimming towards you! You didn’t know anyone could do that, but here comes another insect, gliding across the water like it’s wearing roller skates. You’re safe, it’s going to push you to shore – oh wait never mind, it’s just going to stick its proboscis in you and drain the liquids from your body. Thanks for nothing, pal.

Like I said, I literally knew nothing about water striders before tackling this blog, so the news that these happy-little summertime bugs are vampiric predators kind of rattled me. What’s next, mulch lobsters are actually acid-spraying psychopaths?

Just kidding, mulch lobsters don’t spray acid. Probably.

One thing I did set out to learn was how the water striders work their magic and dance around on the water. As it turns out, these guys are hairy vampires. They’re covered in tiny, grooved, densely-packed hairs (especially on their feet), which trap air between the striders and the water. It’s like they’re wearing little sandals made of air bubbles that keep their feet from getting wet. They’re classy hairy vampires.

Obviously, water striders’ fancy feet aren’t just for show – there’s more to the appendages than just keeping the insects afloat. The reason I thought water striders only had four legs is because the front two legs, which the striders use to hold onto their prey while feasting, are much smaller than their middle and back legs and aren’t really used in the gliding process. The other four legs have specialized functions to get the strider striding. The middle legs propel the insect forward, sometime at incredible speeds if the strider needs to make a quick escape, while the back legs help it steer and brake.

And now for a fact I really didn’t want to know after learning of yet another fluid-draining arthropod – they have wings. Ironically, it’s as if the only place water striders can’t go is under the water. Striders typically have wings so that they can fly to new bodies of water if their current home dries up or becomes uninhabitable, but some generations of striders may be born without wings if their current pond or lake is healthy and unlikely to deteriorate quickly. Water striders that live on the sea almost never have wings, which makes sense since they’re probably not running out of ocean anytime soon.

I’m so glad I looked up water striders before one decided to randomly fly up in my face at the lake. It’s never happened to me before, but if it ever does, at least I’m prepared for it now. And so are you – there are perks to reading a blog about bugs and lobsters after all.