A couple of years ago, an article in the Science magazine reported the alarming cleanliness of car windshields—cleanliness not as in lack of dust or mud, but in lack of insects.
The author, wondering ‘where have all the insects gone’, reported the concerning findings of the Krefeld Entomological Society in Germany, who had been monitoring insect populations already since the beginning of the 1900’s. Members of the Society have seen a dramatic decline in insect species and populations, in some cases reaching 80% between 1989 and 2013.
Scientists have already been extensively reporting the pressures faced by bees, but this time the report considered all sorts of insects, less popular and more overlooked. Similar trends have been noted in Scotland by Rothamsted researchers.
Now a new comprehensive review appeared in the Journal of Biological Conservation, discussing the decline of insects worldwide and the drivers behind these massive decreases. The authors perform meta-analysis on 40 years of published research and report that a stunning 40% of insect species globally are threatened with extinction.
The main reasons behind this alarming situation are habitat loss and pollution. More and more wild areas are re-purposed for intensive agriculture or urbanization. Climate change alters ecosystems and affects insect distribution and abundance. Chemical pollutants leaching from urban, mining and industrial activity, and widespread pesticide use in agricultural practices, have lethal effects on insects and on other species that the insects depend on.
Big deal, you may think—so what if we get less bugged by annoying bugs? Well, not quite. First of all because ‘good’ bugs often control the populations of other bugs that attack crops—think of lady bugs eating their weight in harmful aphids every day, for example. Insects aerate the soil, recycle nutrients and fertilize/create new soil.
They pollinate plants, and there is barely any agricultural produce if plants are not pollinated. Insects produce substances of high economic value—think honey, wax, silk, and even bee venom, which is used in anti-cancer research.
Insects are themselves food for other species. Actually, bird and amphibian populations that depend on insects are already in steep decline, and food webs may well collapse in the event of a massive insect extinction. Conservation and rehabilitation of natural ecosystems, control of contamination and drastic reduction in the use of agricultural pollutants are becoming imperative.