How roaches avoid deadly zombification—and more breakthroughs

Parasitic emerald jewel wasps try to turn roaches into zombies, but roaches know how to escape—most of the time.

How roaches avoid deadly zombification—and more breakthroughs

Parasitic emerald jewel wasps try to turn roaches into zombies, but roaches know how to escape—most of the time.

These stories appear in the March 2019 issue of National Geographic magazine.

“How Not to Be Turned Into a Zombie”—that’s what biologist Kenneth Catania titled his report on the parasitism of American cockroaches by emerald jewel wasps. If stung in the brain, the roach will follow the wasp into a hole where the wasp lays an egg, then seals the hole, leaving the roach to be food for the larva. But in Catania’s study, roaches that vigorously kicked and parried with their legs evaded the stings 63 percent of the time. Read more about the karate cockroach and other hard-kicking animals.

How poppies got power

Humans have long derived morphine and codeine from opium poppies. But how did the flowers evolve to have pain-killing powers? Messily. The poppy’s DNA shows that over more than 110 million years, most of its genome duplicated twice and two extra genes fused into one that’s crucial for narcotic formation. The find may contribute to advances in opiates, which remain vital despite their addictiveness. —Michael Greshko

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Clear and strong

Glasswing butterflies are called espejitos—little mirrors—in their native South America. Wings that are transparent (because they have no colored scales) give them both camouflage and a delicate look. But that’s deceiving: Some glasswings can carry nearly 40 times their own weight. —Patricia Edmonds

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Pollution comes in tiny, toxic packages

The knot of microfibers below is less than four millimeters across, roughly the size of tiny aquatic organisms known as plankton. Every week scientist Richard Kirby sets sail from the coast of Plymouth, England, trailing a net behind his yellow boat to gather plankton—but lately he finds nearly as much plastic in his catch. More than 600,000 tons of plastic microfibers are estimated to enter the ocean each year, shed from fleece, polyester, and other synthetic fabrics during washing. Plankton may eat them or get tangled in them, and the ecological impacts are under study. “Our pollution has extended right down to the bottom of the marine food chain,” Kirby says. “We’ve changed the plankton for the foreseeable future, for hundreds of years or possibly thousands.” —Alejandra Borunda

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National Geographic is committed to reducing plastics pollution. Learn more about our nonprofit activities at natgeo.org/plastics. This story is part of Planet or Plastic?—our multiyear effort to raise awareness about the global plastic waste crisis. Learn what you can do to reduce your own single-use plastics, and take your pledge.