The Creature that Runs So Fast it Goes Blind!
At least, beetles rule when it comes to the number of species. Species of beetles constitute about 25% of all known life-forms on Earth. In the insect realm, 40% of all insect species are beetles, numbering about 350,000. Every year, dozens of new species are discovered, and some believe the number of unclassified beetle species could be into the millions.
Beetles are classified in the order, Coleoptera. This term, first coined by Aristotle, means “sheathed wing,” as this beautiful Maybug beetle illustrates:
Beetles comes in a staggering variety of forms:
But of all the beetles, my favorite is the ferocious and well-named tiger beetle.
Meet the Amazing Tiger Beetle
The tiger beetles is just as ferocious as it looks, and got it’s name from how it hunts like a tiger. It uses its huge eyes to locate and stalk its prey. Once prey is spotted, the tiger beetle runs it down, pounces on it, and tears it to shreds with its huge sword-like mandibles.
Tiger beetles eat other beetles, flies, caterpillars, ants, grasshoppers, spiders and additional invertebrates. And be warned: if you try to catch one with your hands, it will give you a very painful bite that draws blood! (I speak from experience on this!)
As fearsome as they are, these miniature monsters are some of the most beautiful beetles in the world, and often come in brilliant colors:
On Land, the Fastest Insect in the World
There are many bigger and stronger beetles than the tiger beetle. What really sets the tiger beetle apart from other beetles is its speed. In the insect world, nothing runs faster on the ground. I can remember many a fruitless chase as a young boy in the Mojave Desert trying to catch one of these little speed demons. The only thing faster on the dunes was the Zerbra-tailed lizard, probably the fastest lizard in the world.
So, just how fast do these little monsters run? Cole Gilbert, a professor of entomology at Cornel, worked with some American tiger beetles that ran about 1.2 mph or .53 meters per second. That may not sound very fast, until you take into account the scale of the insect. Let’s compare the tiger beetle’s relative speed to that of the fastest human in the world.
The Fastest Human in the World
For our comparison, let’s use the fastest man in the word: Jamaican sprinter Usain Bolt. During the 100 meter dash, he has reached the astonishing top speed of 12.27 m/s or 44.17 km/hr (27.3 mph).
Since Bolt is 1.96 metres (6 ft 5 in) tall, at top speed he is covering over 6 times his body length every second! In other words, Bolt can run 6 bl/s. Pretty impressive! But now let’s compare Bolt’s relative speed to that of Dr. Gilbert’s tiger beetle.
The Tiger Beetle’s Astonishing Speed Relative to Its Size
The species of tiger beetle that Gilbert’s studied is 10 millimeters long, not quite half an inch. At top speed, the beetle is moving 1.2 mph or .53 meters a second. That means the little beetle is ripping along at 53 body lengths a second, almost 9 times as fast as Bolt in relative terms.
In other words, the relative speed of a human-sized tiger beetle running at 53 bl/s would over 240 mph! Imagine a 200-pound tiger chasing you that could run faster than Dale Earnhardt’s race car!
But Dr. Gilbert’s tiger beetle is far from being the relative speed champ. That title belongs to Australian tiger beetle, Cicindela eburneola (subgenus Rivacindela). This amazing insect runs 1.86 m/s (4.16 mph) or an incredible 171 bl/s!
To convert this tiger beetle’s astonishing relative speed into human terms: a Usain Bolt-sized tiger beetle moving at 171 body lengths per second would be moving at about 1097 feet per second or approximately 748 mph! This speed would break sound barrier at sea level (732 mph)! And it would only be a little slower than the Thrust SSC (SuperSonic Car) which went 1,228 km/h (763 mph) breaking the sound barrier at a higher altitude.
[Qualification - Yes, there is another Australian tiger beetle that's even faster in terms of absolute speed. The species Cicindela hudsoni can reach a top speed of 2.5 m/s or 5.6 mph. However, being a larger insect, C. hudsoni's relative speed is "only" 120 bl/s, which translates to a relative speed of "only" 520 mph, merely the cruising speed of a passenger jet!]
Of course, the land animal holding the absolute speed record is the amazing cheetah. As I explained in a previous post, it’s can explode to 65 mph in just 3 seconds, faster than a 660 horsepower Ferrari!
The Tiger Beetle—So Fast It Goes Blind!
Clearly, whether you consider absolute or relative speed, the tiger beetle is one fast insect. If you’re a small insect and the tiger beetle spots you, and you can’t fly away or hide, you are doomed. You aren’t going to outrun those ferocious jaws of death.
Unless….the tiger beetle is running so fast he doesn’t even see you, because it’s virtually blind!
As Dr. Gilbert explains, “If the tiger beetles move too quickly, they don’t gather enough photons (illumination into the beetle’s eyes) to form an image of their prey. Now, it doesn’t mean they are not receptive. It just means that at their speed during the chase, they’re not getting enough photons reflected from the prey to make an image and locate the prey. That is why they have to stop, look around and go. Although it is temporary, they go blind.”
Imagine being able to run so fast that things go dark at top speed , because your eyes aren’t getting enough light and the visual info is coming in faster than your brain can process! That, my friends, is fast! When you consider the relative speed of tiger beetles, it makes sense. If we could sprint to near the speed of sound in seconds, no doubt our eyes and brains would be unable to process what we saw too!
When I watched tiger beetles hunt on sand dunes in the Mojave desert, I was always amazed and puzzled by their stop and start behavior. In a blink of an eye, they’d take off, become a blur, stop in an instant, and then zoom off again. It wasn’t until decades later that I learned the science behind this interesting herky-jerky behavior.
The Summer, Look for Tiger Beetles!
Tigers beetles are found throughout the world, and there are more than a hundred species in the United States. They typically live along sea and lake shores, on sand dunes, around dried lakebeds, and on woodland paths. They are particularly fond of sandy surfaces.
This summer, keep an eye open for these amazing speed-demon predators. Tiger beetles aren’t huge, but there’s no mistaking their beautiful coloration, their bulging eyes, and those incredible jaws. No beetle or insect on the ground will be moving as fast. And when you see them stop and start in bursts of speed, you’ll know why: these amazing beetles run so fast, they go blind and have to stop to see where they are!
If you’re an insect being chased by a tiger beetle, you’d better hope you can hide or fly away during that very brief blind period, because you’ll never outrun this speed king of insects!