Insect loss is devastating
Monday, March 25, 2019
The Portland, Maine, Press Herald
This may surprise anyone who’s been caught outside on an early summer night in Maine, 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 that the loss is worldwide. About 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.
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. 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. “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, said. “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 is to blame, as well as climate change. Those factors have led to habitat loss, the widespread use of synthetic pesticides and fertilizers, and increasingly inhospitable temperatures in the tropics.
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.
That’s where Maine is pitching in. The Department of Inland Fisheries & Wildlife is teaming with Maine Audubon to study the decline here, where there are anecdotal signs of losses in butterflies, dragonflies, beetles and other insects.
We should pay attention to the study. There are many good reasons for fighting climate change, and for moving away from large-scale industrial agriculture. Saving insects — the building blocks of our ecosystems — may not be the most popular, but it may be one of the most important.