A tiny insect called Paratarsotomus macropalpis can give a cheetah a run for its money when it comes to speed. Relative to its body size, the little mite can run at surprising speeds covering distances a few hundred times longer than its body size in a single second.
While the cheetah is popularly known as one of the fastest animals on land, scientists have known for a while now that insects can actually move faster relative to body size. The previous holder of the title of the fastest land based organism was the Australian tiger beetle, which could run at a speed of 171 body lengths every second. On the other hand, a cheetah can run at around 16 body lengths every second. However, these speed demons pale in comparison to P. macropalpis. The tiny mite is only around the size of a sesame seed but it can travel an astounding 322 body lengths in a single second.
"It's so cool to discover something that's faster than anything else, and just to imagine, as a human, going that fast compared to your body length is really amazing," said Pitzer College physics major Samuel Rubin. "But beyond that, looking deeper into the physics of how they accomplish these speeds could help inspire revolutionary new designs for things like robots or biomimetic devices." Rubin worked in the field in an effort to record the insect's actual speed.
Seen from the eyes of humans, insects don't really move at impressive speeds. If P. macropalpis were the same size as humans however, the mite would be able to move at a blistering speed of 1,300 mph. Rubin was aided by his advisor Jonathan Wright. The Pomona College based biology professor was studying the biochemistry of animal muscles and he grew curious about the mite in question. After Rubin and his team came back with the data gathered from the field, the researchers were able to determine that P. macropalpis is indeed the fastest animal on land.
"We were looking at the overarching question of whether there is an upper limit to the relative speed or stride frequency that can be achieved," said Wright. "When the values for mites are compared with data from other animals, they indicate that, if there is an upper limit, we haven't found it yet."
Due to the tiny size of the mite as well as the speed of its movements, the researchers had difficulty measuring how fast they were actually moving. To accurately measure the insect's movement speed, the researchers needed to record everything using a high speed camera. Once the footage was recorded, the team went back to the lab to analyze the results using the camera's frame speed to calculate the insect's speed. Scientists are hoping to gain a deeper understanding regarding the limitations of land based animal locomotion. The researchers presented their data at the annual meeting of Experimental Biology.
