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      in Physics

      The diabolical ironclad beetle can survive getting run over by a car. Here’s how

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      The diabolical ironclad beetle is like a tiny tank on six legs.
      This insect’s rugged exoskeleton is so tough that the beetle can survive getting run over by cars, and many would-be predators don’t stand a chance of cracking one open. Phloeodes diabolicus is basically nature’s jawbreaker.
      Analyses of microscope images, 3-D printed models and computer simulations of the beetle’s armor have now revealed the secrets to its strength. Tightly interlocked and impact-absorbing structures that connect pieces of the beetle’s exoskeleton help it survive enormous crushing forces, researchers report in the Oct. 22 Nature. Those features could inspire new, sturdier designs for things such as body armor, buildings, bridges and vehicles.
      The diabolical ironclad beetle, which dwells in desert regions of western North America, has a distinctly hard-to-squish shape. “Unlike a stink beetle, or a Namibian beetle, which is more rounded … it’s low to the ground [and] it’s flat on top,” says David Kisailus, a materials scientist at the University of California, Irvine. In compression experiments, Kisailus and colleagues found that the beetle could withstand around 39,000 times its own body weight. That would be like a person shouldering a stack of about 40 M1 Abrams battle tanks.
      Within the diabolical ironclad beetle’s own tanklike physique, two key microscopic features help it withstand crushing forces. The first is a series of connections between the top and bottom halves of the exoskeleton. “You can imagine the beetle’s exoskeleton almost like two halves of a clamshell sitting on top of each other,” Kisailus says. Ridges along the outer edges of the top and bottom latch together.
      This slice of a diabolical ironclad beetle’s back shows the jigsaw-shaped links that connect the left and right sides of its exoskeleton. These protrusions are tightly interlocked and highly damage-resistant, helping give the beetle its incredible durability.David Kisailus
      But those ridged connections have different shapes across the beetle’s body. Near the front of the beetle, around its vital organs, the ridges are highly interconnected — almost like zipper teeth. Those connections are stiff and resist bending under pressure.
      The connective ridges near the back of the beetle, on the other hand, are not as intricately interlocked, allowing the top and bottom halves of the exoskeleton to slide past each other slightly. That flexibility helps the beetle absorb compression in a region of its body that is safer to squish.
      The second key feature is a rigid joint, or suture, that runs the length of the beetle’s back and connects its left and right sides. A series of protrusions, called blades, fit together like jigsaw puzzle pieces to join the two sides. These blades contain layers of tissue glued together by proteins, and are highly damage-resistant. When the beetle is squashed, tiny cracks form in the protein glue between the layers of each blade. Those small, healable fractures allow the blades to absorb impacts without completely snapping, explains Jesus Rivera, an engineer at UC Irvine.

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      This toughness makes the diabolical ironclad beetle pretty predator-proof. An animal might be able to make a meal out of the beetle by swallowing it whole, Kisailus says. “But the way it’s built, in terms of other predation — let’s say like a bird that’s pecking at it, or a lizard that’s trying to chew on it — the exoskeleton would be really hard” to crack.
      That hard exterior is also a nuisance for insect collectors. The diabolical ironclad beetle is notorious among entomologists for being so fantastically durable that it bends the steel pins usually used to mount insects for display, says entomologist Michael Caterino of Clemson University in South Carolina. But “the basic biology of this thing is not particularly well-known,” he says. “I found it fascinating” to learn what makes the beetle so indestructible.
      The possibility of using beetle-inspired designs for sturdier airplanes and other structures is intriguing, Caterino adds. And with the splendid variety of insects all over the world, who knows what other critters might someday inspire clever engineering designs. More

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      in Heart

      Penguin poop spotted from space ups the tally of emperor penguin colonies

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      Patches of penguin poop spotted in new high-resolution satellite images of Antarctica reveal a handful of small, previously overlooked emperor penguin colonies.
      Eight new colonies, plus three newly confirmed, brings the total to 61 — about 20 percent more colonies than thought, researchers report August 5 in Remote Sensing in Ecology and Conservation. That’s the good news, says Peter Fretwell, a geographer at the British Antarctic Survey in Cambridge, England.
      The bad news, he says, is that the new colonies tend to be in regions highly vulnerable to climate change, including a few out on the sea ice. One newly discovered group lives about 180 kilometers from shore, on sea ice ringing a shoaled iceberg. The study is the first to describe such offshore breeding sites for the penguins.

      Penguin guano shows up as a reddish-brown stain against white snow and ice (SN: 3/2/18). Before 2016, Fretwell and BAS penguin biologist Phil Trathan hunted for the telltale stains in images from NASA’s Landsat satellites, which have a resolution of 30 meters by 30 meters.
      Emperor penguins turned a ring of sea ice around an iceberg into a breeding site. The previously unknown colony was found near Ninnis Bank, a spot 180 kilometers offshore, thanks to a brown smudge (arrow) left by penguin poop.P.T. Fretwell and P.N. Trathan/Remote Sensing in Ecology and Conservation 2020
      The launch of the European Space Agency’s Sentinel satellites, with a much finer resolution of 10 meters by 10 meters, “makes us able to see things in much greater detail, and pick out much smaller things,” such as tinier patches of guano representing smaller colonies, Fretwell says. The new colony tally therefore ups the estimated emperor penguin population by only about 10 percent at most, or 55,000 birds.
      Unlike other penguins, emperors (Aptenodytes forsteri) live their entire lives at sea, foraging and breeding on the sea ice. That increases their vulnerability to future warming: Even moderate greenhouse gas emissions scenarios are projected to melt much of the fringing ice around Antarctica (SN: 4/30/20). Previous work has suggested this ice loss could decrease emperor penguin populations by about 31 percent over the next 60 years, an assessment that is shifting the birds’ conservation status from near threatened to vulnerable. More

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      in Heart

      Power lines may mess with honeybees’ behavior and ability to learn

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      Power lines could be messing with honeybees by emitting electromagnetic fields that can alter the insects’ behavior and ability to learn. In the lab, honeybees (Apis mellifera) were more aggressive toward other bees after being exposed to electromagnetic fields, or EMFs, at strengths similar to what they might experience at ground level under electricity transmission […] More

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      in Heart

      Humpback whales use their flippers and bubble ‘nets’ to catch fish

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      Humpback whales need to eat a lot every day, and some even use their flippers to help snag a big mouthful of fish. Researchers filmed humpbacks (Megaptera novaeangliae) hunting with this tactic, called pectoral herding, off the Alaskan coast. It’s the first time that this behavior has been documented in such detail, the team reports […] More