Not just winter warming causes pine beetle plague – it’s the springs and summers too!

mountain pine beetles The American Naturalist
Some journals walk at a different pace – which of course makes them all the more charming. Meet The American Naturalist: “First published in 1867, it is the oldest scientific journal in the world dedicated to the study of ecology, evolution, and behavior.” It is proudly presented by the American Society of Naturalists [indeed, you’ve guessed it – the oldest scientific society dedicated to the study of ecology, evolution, behavior.]

Today they are in the news, but the actual publication is in no hurry, plagues and climatic changes or not.

If you haven’t been swamped by other interesting stuff by that time, do please order their May number. It is about mountain pine beetles [interesting by definition] – and to be fair there is already quite a bit to read in advance on the Naturalist website.

The ever-spreading plague of pine beetles, which larvae infest pine trees after which the trees die, is not just caused because in milder winters the beetles do no longer freeze to their deaths, new research by the University of Colorado shows. Climate change proves an all-year-round thing.

In the Rocky Mountains test site over the last two decades average annual temperatures have risen considerably, by 1.5 degrees Celsius, or 2.7 degrees Fahrenheit. Spring warming has been most notable though – and the number of spring days with temperatures above freezing increased by 15.1, the researchers say. Since 1970 the number of days that pine beetle larvae can grow to the state of adult beetle, has increased by 44 percent.

The test site lies at an altitude 10,000 feet, higher than the historical range for mountain pine beetles. The uphill creep [adult pine beetles can actually fly btw] of the beetles is however not the only warming consequence. The Colorado researchers say they have also discovered that the pine beetles now manage to complete two breeding cycles in one summer.

Well then, small wonder there are more beetles around these days.

It is not the only ecological consequence of climate change in the insect world, in that same place. Just today we learn how the earlier onset of spring snowmelt leads to flower and butterfly decline. Next thing you tell us these nice golden aspen trees will be affected by warming too. Well, wait for it – afraid there are reports around. When the Rocky Mountains snows go they leave a desolate place. No business for her to stay either.

© Rolf Schuttenhelm |

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