Decline in insects is not good news

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This may surprise anyone who’s been caught outside on an early summer night in upstate New York, but the number of insects is declining rapidly — and that’s not good for anyone.

The first global review of reports of insect population decline confirmed what researchers have feared for a while —that the loss, rather than just regional, is in fact worldwide. Around 41 percent of all insect species have seen a decline in the last 10 years, the study said. By weight, insects are dying off at a rate of 2.5 percent per year, and have been for some time — which would mean complete disappearance within a century.

Some examples of the harm already, the study said, are the loss of 58 percent of butterfly species on English farmland from 2000 to 2009, and the disappearance of half of all bee species in Oklahoma from 1949 to 2013.

The dire evidence aligns with earlier studies. One found a 76 percent decrease in flying insects over just a few decades in German nature preserves. Another study, which returned to the Puerto Rican rain forest after 40 years, found almost no butterflies, and far fewer birds. Moths, grasshoppers and spiders were disappearing, too; the number of frogs and birds was cut in half.

The decline of non-insect species shows how interconnected these ecosystems are — it is impossible to lose a component as essential as insects and not see a change in the lives of other, dependent species.

“Two out of every three species on Earth is an insect, and they represent an incredible diversity,” Bob Peterson, president of the Entomological Society of America, told National Public Radio about the most recent study. “Without insects, and what they do in our landscape, in our ecosystems, many of those ecosystems would completely collapse.”

The latest study says changes in agriculture and land use could be to blame. All of it is alarming — but scientists are still quite in the dark when it comes to the population collapse of insects. To figure out just what is happening, why and what to do about it, more information is needed.

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