Beetles’ birth explosion adds stress to trees

April 22, 2012 

Mountain pine beetles attack and kill weak pine trees, boring into bark to lay their eggs. They attack the trees in hordes, and their larvae feed off fungi in the trees. Now, the beetles are reproducing twice a year instead of once, and millions of trees are dying as a result.

Historically, the beetle larvae grow to be adults in July or August every year. But it has been getting warmer earlier in the year, and larvae mature faster and emerge as early as May. These new beetles then immediately lay eggs, and a second generation of adult beetles emerges as early as July because summers are so warm, said Scott Ferrenberg, an evolutionary biologist at the University of Colorado at Boulder and an author of a study in the coming issue of The American Naturalist.

The researchers did their work in Colorado at an elevation of 10,000 feet. Several decades ago, pine beetles were not found at that elevation, Ferrenberg said. “The invasion of that habitat above 9,000 feet has happened after several decades of significant warming,” he said.

He called the beetle phenomenon an epidemic, not limited to mountain pine beetles.

Other trees are also under stress from other species of beetles.

“Spruce beetles and Douglas fir beetles are at epidemic levels,” he said. And southern pine beetles, typically found in the American South, are moving north.

New York Times

Toddlers and chimps follow the crowd

Many a parent may say that teenagers succumb to peer pressure. A new study reports that toddlers and chimpanzees do too – but orangutans, on the other hand, don’t seem to follow the crowd.

Daniel Haun, a psychologist at the Max Planck Institutes for Evolutionary Anthropology and Psycholinguistics, and his colleagues reported their findings in the journal Current Biology.

To conduct their study, they created a box with three colored holes. A treat appeared only when a ball was dropped into a particular hole. Toddlers, chimpanzees and orangutans each watched as four members of their species who knew how the box worked interacted with it. The observers were then given a chance to seek a treat themselves.

Toddlers and chimps tended to follow the behavior of the majority, while the orangutans seemed to choose a hole at random.

“One of the big differences is that chimps and humans continue to live in large social groups when they grow up,” Haun said. “Orangutans don’t.”

New York Times

More to see and do at N.C. Science Festival

The N.C. Science Festival is midway through its multi-event, multi-date run, and ample opportunities remain for you to get involved in STEM research.

That’s the acronym for “science, technology, engineering and mathematics,” and piquing your interest in these fields is what’s behind the statewide festival, which continues through April 29. It’s produced by UNC Chapel Hill’s Morehead Planetarium and Science Center; with corporate and foundation sponsors, the festival is staging hundreds of public activities and displays.

Too busy during the work/school week? Events next weekend include the N.C. Science Olympiad – a tournament of school projects, with close to 200 teams – at N.C. State’s Reynolds Coliseum, 9 a.m.-3 p.m. April 28. Admission is free. Info:

Festival details/schedule:

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