Overige insecten

A while back we took note of a study that showed populations of airborne insects have declined by 76 percent in protected areas in Germany over the past 27 years. Part of the picture was that the disappearance of bugs is likely to pose problems for other animals in the food chain. Now a recent study by French scientists revealed that bird populations in France’s farming areas have declined by more than one-third in the past 17 years. Both resident and migrant species have decreased sharply.

Europe’s crisis of collapsing bird and insect numbers will worsen further over the next decade because the EU is in a “state of denial” over destructive farming practices, environmental groups are warning. European agriculture ministers are pushing for a new common agriculture policy (CAP) from 2021 to 2028 which maintains generous subsidies for big farmers and ineffectual or even “fake” environmental or “greening” measures, they say.

Die Biologin Rachel Carson begann ihr berühmt gewordenes Buch einst mit einem Zukunftsmärchen. Sie schildert eine Stadt inmitten blühender Obstgärten. Entlang der Straßen entzücken Schneeballsträucher, hohe Farne und wilde Blumen das Auge. Die Vogelwelt ist artenreich, in den Bächen tummeln sich Fische. Doch dann rafft eine seltsame, schleichende Seuche Mensch und Tier dahin. Bäume und Blüten verkümmern. Die wenigen, noch übrig gebliebenen Vögel zittern und können nicht mehr singen. Es sei ein „stummer Frühling“, gewesen, schreibt sie in ihrem gleichnamigen, 1962 erschienenen Buch.

"You are what you eat" is the guiding principle behind a new study comparing the diet of birds today with that of birds dead for more than a century. The results show large changes in the diets of aerial insectivores, or birds such as swallows, swifts, martins and whip-poor-wills that consume insects while in mid-flight. Today, the bulk of the birds' diet is made up of small insects at the lower end of the food web, or at a lower "trophic" level, the researchers say.

Neonicotinoid use has increased rapidly in recent years, with a global shift toward insecticide applications as seed coatings rather than aerial spraying. While the use of seed coatings can lessen the amount of overspray and drift, the near universal and prophylactic use of neonicotinoid seed coatings on major agricultural crops has led to widespread detections in the environment (pollen, soil, water, honey).

Over the past 15 years, neonicotinoid seed treatments have been adopted worldwide and are used on a large proportion of U.S. field crops. Although neonicotinoids are used widely, little is known about how large-scale deployment affects pest populations over long periods. Here, we report a positive relationship between the deployment of neonicotinoid seed-dressings on multiple crops and the emergence of insecticide resistance in tobacco thrips (Frankliniella fusca), a polyphagous insect herbivore that is an important pest of seedling cotton but not soybean or maize.

The State of the Nations Butterfly report which is published every five years shows long term and ten year trends – and it’s waving a danger flag. The most recent report published in 2015 indicates that overall a staggering 76 percent of our butterflies declined in abundance and occurrence over the past 40 years.

Four species of butterfly have become extinct over the past 150 years and the rest face an uncertain future. Our moths are doing no better as the total number over the past 40 years has declined overall by 28 percent, even as low as 40 percent in southern areas.

The neonicotinoid insecticide imidacloprid is used in Bangladesh for a variety of crop protection purposes. Imidacloprid may contaminate aquatic ecosystems via spray drift, surface runoff and ground water leaching. The present study aimed at assessing the fate and effects of imidacloprid on structural (phytoplankton, zooplankton, macroinvertebrates and periphyton) and functional (organic matter decomposition) endpoints of freshwater, sub-tropical ecosystems in Bangladesh.