House Centipedes Use Their Legs Like Lassos to Catch Prey

iStock.com/Ivan Marjanovic
iStock.com/Ivan Marjanovic

You thought house centipedes were already creepy enough without needing to know the graphic details of how they catch and kill their prey. But in case you were wondering, they sometimes use their legs like lassos to rope in and restrain their victims, London-based paleontologist Greg Edgecombe tells Deep Look, a web series created by KQED San Francisco and presented by PBS Digital Studios. That's not the only way they use their legs, either. “Basically arthropods are Swiss army knives,” Edgecombe says. “They differentiate the legs for different functions.”

In addition to using their flexible legs to put their prey in a triangle choke like an agile MMA fighter, they may even use their long hind legs in mating rituals. Their back legs contain as many sensory hairs as their antennae, and the two parts are often confused because they are similar in both length and appearance. Researchers say centipedes do a kind of ritual courtship dance in which the male and female arthropods raise and lower their back legs and antennae. There’s also some “mutual tapping and probing” involved.

The insects are cannibalistic, venomous, and exceptionally fast runners—but don’t worry, they rarely bite humans. Their long fangs, known as forciples, are actually modified legs. The forciples are not only used to hold their defenseless prey in place and inject venom, but also to clean and lubricate the sensory hairs along their legs.

By the way, despite popular belief, centipedes usually don’t have 100 legs. Most species have fewer than 60, and baby centipedes only have eight. As they grow, they develop more and more legs.

If you aren’t thoroughly grossed out by now, check out Deep Look’s creepy, crawly video below, featuring none other than the humble house centipede.

[h/t The Kids Should See This]

Why You Should Never Squish a Stink Bug

iStock.com/drnadig
iStock.com/drnadig

Commit the insect you see above to memory. That’s the brown marmorated stink bug, an invasive species originally from Asia that’s made inroads across large sections of the United States, including the Mid-Atlantic.

If you come across one, don’t squish it. In fact, don’t even nudge it. A stink bug’s pestilence can survive after death. And you can probably guess how.

According to The State, stink bugs release a secretion that smells absolutely awful when they’re disturbed or feel threatened. Stomping them just expedites the liquid. Those who have had the unfortunate opportunity to get a whiff have described it as resembling skunk odor or rotten cilantro.

In winter, the bugs tend to find their way indoors, where their half-inch bodies tend to catch the eye of homeowners. Fortunately, they’re largely harmless, and are not known to carry diseases or be destructive to pets or property. (Crops are an exception: The stinkbugs can prove damaging to agriculture.) While exterminators can treat houses, some recommend just ignoring them.

If you want a DIY approach, you can try vacuuming them up or leaving out trays with soapy water. The mixture will kill the bugs and minimize any post-mortem secretion.

Since the bugs were first spotted in Allentown, Pennsylvania around 1998, they’ve been spotted in 43 states. Generally, you probably won’t see more than a few in your home, though they’ll definitely congregate if conditions are right. One wildlife biologist in Maryland suffering from an infestation counted 26,000 stink bugs in his residence.

The good news? Scientists have determined that the stinkbug’s natural predator, the samurai wasp, is in hot pursuit. Entomologists at the U.S. Department of Agriculture had made plans to bring the wasp over from Asia to help control the bug population but discovered in 2014 that the wasp had somehow made the journey on its own. Their idea of population control is injecting their own eggs into a stinkbug’s, its larvae eating the pest. The parasitic wasp is in 10 states and climbing.

[h/t The State]

New Study Reveals 'Hyper-Alarming' Decline of Rainforest Insect Populations

iStock/jmmf
iStock/jmmf

Climate change is decimating yet another vital part of the world's ecosystem, according to a startling new paper. Rainforest insects are dying off at alarming rates, according to a new study spotted by the The Washington Post. In turn, the animals that feed off those insects are decreasing, too.

In the study, published in Proceedings of the National Academy of Sciences, a pair of scientists from the Rensselaer Polytechnic University in New York and the National Autonomous University of Mexico studied populations of rainforest arthropods (an invertebrate classification that includes insects and spiders) in the El Yunque National Forest in Puerto Rico. They compared the number of insects lead author Bradford Lister found on trips in 1976 and 1977 with the number he and co-author Andres Garcia found on trips they took between 2011 and 2013.

Lister and Garcia used nets and sticky traps to collect insects on the ground and several feet above the ground in the forest canopy. They dried these captured bugs and measured the mass of their haul against the mass of insects found in the 1970s, finding that the modern net sweeps captured only an eighth to a fourth of the insects captured in the '70s. The mass of insects captured by sticky traps on the ground declined by 30 to 60 times what they were a few decades ago. They also tracked populations of lizards, frogs, and birds that live off those rainforest insects, finding that those populations had declined significantly, too, at levels not seen in other rainforest animals that don't rely on insects for food.

Tropical insects are particularly vulnerable to climatic changes, since they can't regulate their body temperature. During the time of the study, average maximum temperatures in El Yunque rose by almost 4°F (2°C). The warming climate is "the major driver" of this decline in arthropod populations, the study authors write, triggering a collapse of the forest food chain.

The paper has other scientists worried. "This is one of the most disturbing articles I have ever read," University of Connecticut entomologist David Wagner, who wasn't involved in the research, told The Washington Post, calling the results "hyper-alarming." Other studies of insect populations have found similarly dire results, including significant declines in butterflies, moths, bees, and other species. One recent study found that Germany's flying insect populations had decreased by as much as 75 percent in the last three decades. Scientists don't always attribute those population losses directly to warmer temperatures (habitat loss, pesticide use, droughts, and other factors might play a role), but it’s clear that insect populations are facing grave threats from the modern world.

Not all insect species will be equally affected by climate change, though. While we may see a sharp drop in the populations of tropical insects, scientists project that the number of insects in other regions will rise—leading to a sharp increase in crop-eating pests in some parts of the world and broadening mosquitos' geographical range.

[h/t The Washington Post]

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