De globale insectenpopulatie is op weg richting een totale uitroeiing als de trend van de afgelopen dertig jaar zich voortzet. Binnen enkele decennia dreigt er geen enkel insect meer te zijn op onze planeet. De gevolgen zullen catastrofaal zijn voor de “natuurlijke ecosystemen”, maar ook voor “de overlevingskansen van de mensheid”. Dat stellen twee wetenschappers, onder wie een Belg, in de eerste wereldwijde studie over het onderwerp.
Pesticide use is driving an “alarming” decline in the world’s insects that could have a “catastrophic” impact on nature’s ecosystems, researchers have warned. More than 40 per cent of insect species are at risk of extinction with decades, with climate change and pollution also to blame, according to a global scientific review. Their numbers are plummeting so precipitously that almost all insects could vanish within a century, the study found.
When American entomologist Bradford Lister first visited El Yunque National Forest in Puerto Rico in 1976, little did he know that a long-term study he was about to embark on would, 40 years later, reveal a “hyperalarming” new reality. In those decades, populations of arthropods, including insects and creepy crawlies like spiders and centipedes, had plunged by an almost unimaginable 98% in El Yunque, the only tropical rainforest within the US National Forest System.
The researchers measured the forest’s insects and other invertebrates, including spiders and centipedes by using trap methods with sticky plates and nets in the canopy. They collected the critters and larvae that crawled through the vegetation and examined the density of population. Each technique revealed that the dry weight of the captured insects were very less when compared to 1976. The researchers observed that there has been a significant decline in the population of insects of all species since 1976.
Auf Einladung des Bund für Umwelt und Naturschutz Deutschland (BUND) referierte der Insektenforscher Thomas Hörren vom Entomologischen Verein Krefeld (EVK) im Möllner Quellenhof vor 90 Besuchern über deren bahnbrechende Studie zum Thema “Rückgang der Insekten-Biodiversität”. An zahlreichen Standorten ausschließlich in Schutzgebieten hatte der EVK 27 Jahre lang die Insektenfauna untersucht. Aufgrund des enormer Datenbestand und der wissenschaftlichen Methodik waren die Entomologen in der Lage, nicht nur den schleichenden Verlust an Arten, sondern auch an Insekten-Biomasse zu dokumentieren.
Arthropods, invertebrates including insects that have external skeletons, are declining at an alarming rate. While the tropics harbor the majority of arthropod species, little is known about trends in their abundance. We compared arthropod biomass in Puerto Rico’s Luquillo rainforest with data taken during the 1970s and found that biomass had fallen 10 to 60 times. Our analyses revealed synchronous declines in the lizards, frogs, and birds that eat arthropods.
Since European settlement, over 100 species have been lost here. These include plants and animals that are extinct and extirpated, and species that are considered historic (no one has seen them in Canada for a long time). The number of lost species varies between different regions of the country. In the Great Lakes region of southern Ontario, there are extinct species (passenger pigeon), extirpated species (paddlefish) and historic species (Eskimo curlew). There are also species that have vanished from this landscape but still exist elsewhere in Canada.
Conservationists are sounding the alarm about turtles in Ontario, warning all eight species in the province are now in trouble. The Committee on the Status of Endangered Wildlife in Canada (COSEWIC), a body of wildlife agents from governments, Indigenous and non-profit entities, designated the midland painted turtle (Chrysemys picta marginata) as a special concern in April. The designation means these types of turtles may soon become threatened or endangered.
Bees tend to get the most attention as pollinators critical to the survival of plant species. But lizards, mice, bats, and other vertebrates also act as important pollinators. A new study finds that fruit and seed production drops an average 63 percent when vertebrates, but not insects, are kept away from plants.
When Lonesome George died in June 2012, it was the end of an entire species. He was the last surviving Pinta giant tortoise (Chelonoidis abingdonii), a Galapagos conservation icon who had lived for more than 100 years. But Lonesome George was not alone in his fate. More than 50 percent of the world’s 356 known species of tortoises and turtles are currently threatened with extinction, or are nearly extinct, a new report warns.