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    Watch a tiny bug do the world’s fastest backflip

    Composite image of a globular springtail jumping. (Credit: Adrian Smith)

    A new study features the first in-depth look at the jumping prowess of the globular springtail (Dicyrtomina minuta).

    This diminutive hexapod backflips into the air, spinning to over 60 times its body height in the blink of an eye.

    Globular springtails are tiny, usually only a couple millimeters in body length. They don’t fly, bite, or sting. But they can jump. In fact, jumping is their go-to (and only) plan for avoiding predators. And they excel at it—to the naked eye it seems as though they vanish entirely when they take off.

    “No other animal on earth does a backflip faster than a globular springtail.”

    “When globular springtails jump, they don’t just leap up and down, they flip through the air—it’s the closest you can get to a Sonic the Hedgehog jump in real life,” says corresponding author Adrian Smith, research assistant professor of biology at North Carolina State University and head of the evolutionary biology and behavior research lab at the North Carolina Museum of Natural Sciences. “So naturally I wanted to see how they do it.”

    Finding the globular springtails was easy enough—they’re all around us. The ones in this study are usually out from December through March. Smith “recruited” his research subjects by sifting through leaf litter from his own backyard. But the next part proved to be the most challenging.

    “Globular springtails jump so fast that you can’t see it in real time,” Smith says. “If you try to film the jump with a regular camera, the springtail will appear in one frame, then vanish. When you look at the picture closely, you can see faint vapor trail curlicues left behind where it flipped through the one frame.”

    Smith solved that problem by using cameras that shoot 40,000 frames per second. He urged the springtails to jump by shining a light on them or lightly prodding them with an artist’s paintbrush. Then he looked at how they took off, how fast and far they went, and how they landed.

    Globular springtails don’t use their legs to jump. Instead, they have an appendage called a furca that folds up underneath their abdomen and has a tiny, forked structure at its tip. When the springtails jump, the furca flips down and the forked tip pushes against the ground, launching them into a series of insanely fast backflips.

    What do we mean by insanely fast?

    “It only takes a globular springtail one thousandth of a second to backflip off the ground and they can reach a peak rate of 368 rotations per second,” Smith says. “They accelerate their bodies into a jump at about the same rate as a flea, but on top of that they spin. No other animal on earth does a backflip faster than a globular springtail.”

    The springtails were also able to launch themselves over 60 millimeters into the air—more than 60 times their own height. And in most cases, they went backward.

    “They can lean into a jump and go slightly sideways, but when launching from a flat surface, they mostly travel up and backward, never forward,” says Jacob Harrison, a postdoctoral researcher at the Georgia Institute of Technology and paper coauthor.

    “Their inability to jump forward was an indication to us that jumping is primarily a means to escape danger, rather than a form of general locomotion.”

    Landing was found in two styles: uncontrolled and anchored. Globular springtails do have a sticky forked tube they can evert—or push out of their bodies—to grapple a surface or halt their momentum, but Smith observed that bouncing and tumbling to a stop was just as common as anchored landings.

    “This is the first time anyone has done a complete description of the globular springtail’s jumping performance measures, and what they do is almost impossibly spectacular,” Smith says. “This is a great example of how we can find incredible, and largely undescribed, organisms living all around us.”

    The work appears in Integrative Organismal Biology.

    Source: North Carolina State University

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    Watch: Jumping ants duel with antennae after the queen dies

    "Despite prolonged social upheaval in ant colonies following the loss of the queen, the winners of these dueling tournaments are rapidly determined," says Claude Desplan. (Credit: IOC Young Reporters/Flickr)

    Changes in behavior and gene expression show which worker will come out on top in the first days of a month-long battle between worker ants to establish new leadership after their queen dies, researchers report.

    “Despite prolonged social upheaval in ant colonies following the loss of the queen, the winners of these dueling tournaments are rapidly determined,” says Claude Desplan, a professor of biology at New York University.

    “Our findings may provide clues on adaptability in reproduction and aging, given that the workers who win the duel, or ‘pseudoqueens,’ gain the ability to lay eggs and live much longer than the average worker ant. This suggests that changes in the environment are able to dramatically affect the structure of a society.”

    The caste system in social insects creates a division of labor, with insects specialized to perform particular tasks. The queen is responsible for reproduction, while workers maintain the colony—caring for the young, foraging and hunting for food, cleaning, and defending the nest.

    In many insect societies, when the queen dies, the entire colony dies along with her due to the lack of reproduction. However, in Indian jumping ants (Harpegnathos saltator), “caste switching” occurs after the queen’s death. While the queen is alive, she secretes pheromones that prevent female worker ants from laying eggs, but when she dies, the workers sense the lack of pheromones and begin fighting each other to take on the top role.

    The ants engage in dueling tournaments, striking each other with their antennae in matches that can last more than a month. While most ants quickly return to their usual work during the tournament, the winners become pseudoqueens—also known as gamergates—and acquire new behaviors and roles. Through this transition, their life expectancy dramatically increases (from seven months to four years) and they begin laying eggs, allowing the colony to survive.

    In their study, the researchers explored changes in the Indian jumping ants’ social behavior and accompanying changes in gene expression during the early stages of the worker-to-pseudoqueen transition.

    They found that, as early as after three days of dueling, the winners can be accurately predicted solely based on the dueling behavior. The workers who triumphed and became pseudoqueens had much higher levels of dueling—sparring roughly twice as much in the first five days—while the others who remained workers dueled less and went back to performing other tasks such as cleaning and hunting.

    “Despite the fact that dueling tournaments last for several weeks, we were able to anticipate which ants would become pseudoqueens in only three days,” says Comzit Opachaloemphan, a doctoral student in the Department of Biochemistry and Molecular Pharmacology at NYU Grossman School of Medicine and one of the study’s lead authors.

    Comparing biological samples and gene expression from dueling versus non-dueling ants, the researchers then determined the changes associated with the worker-to-pseudoqueen transition. Molecular analyses revealed that the brain may be driving the dueling and early caste determination in the ants, with other tissues taking cues from the brain.

    The researchers found that the first genes to respond to the loss of the queen were in the brain, suggesting that the lack of queen pheromones perceived by the olfactory system affects brain neurohormonal factors. These changes in the brain then lead to altered social behavior and hormone-mediated physiological changes in other parts of the body, including the ovaries.

    “Both behavioral and molecular data—especially changes in gene expression in the brain—show us that new pseudoqueens are quickly determined after a colony’s social structure has been disrupted by the loss of the queen,” says study author Danny Reinberg, a professor in the biochemistry and molecular pharmacology department at the Grossman School of Medicine, as well as an investigator for the Howard Hughes Medical Institute.

    The research appears in the journal Genes & Development.

    Support for the research came from a Howard Hughes Medical Institute Collaborative Innovation Award, the National Institutes of Health, EMBO, and the Human Frontier Science Program.

    Source: New York University