Vlinders

Der Insektenrückgang rund um Karlsruhe ist dramatisch

In einer Anfrage an den Gemeinderat will die CDU wissen, wie es um die Insekten bestellt ist und was gegen das Insektensterben in der Fächerstadt getan werden kann. Die Stadt Karlsruhe hat bereits auf die Anfrage der CDU-Fraktion geantwortet. Sie bestätigt einen Rückgang der Insekten als "überregionales Phänomen, zu dem es belastbare Studien gibt". Das Sterben der Insekten in Karlsruhe lässt sich anhand einer der größten Insektengruppen nachvollziehen: Der Schmetterlinge.

Die Zahl der weltweit bedrohten Tier- und Pflanzenarten hat dieses Jahr einen neuen Rekordstand erreicht

Mit rund 25'800 bedrohten Tier- und Pflanzenarten sei im zu Ende gehenden Jahr ein neuer dramatischer Höchststand erreicht worden. Ein Jahr zuvor waren es noch 24'000 bedrohte Arten. "Wir Menschen verursachen das grösste Artensterben seit Ende der Dinosaurier", resümierte Eberhard Brandes, Vorstand des WWF Deutschland. Auch in der Schweiz gingen die Bestände einiger Arten merklich zurück. Mehr als 40 Prozent der Insektenarten in der Schweiz gälten als bedroht, darunter Bienen und Schmetterlinge, sagte WWF-Sprecherin Perrette Rey in Lausanne auf Anfrage.

Neonicotinoid insecticides are driving declines of widespread butterflies

In England, the total abundance of widespread butterfly species declined by 58% on farmed land between 2000 and 2009 despite both a doubling in conservation spending in the UK, and predictions that climate change should benefit most species. Here we build models of the UK population indices from 1985 to 2012 for 17 widespread butterfly species that commonly occur at farmland sites. Of the factors we tested, three correlated significantly with butterfly populations. Summer temperature and the index for a species the previous year are both positively associated with butterfly indices.

The Resilience of the Bee Hive

A recent assessment of higher tier studies on the toxicity and risks of neonics in honeybees by Solomon and Stephenson reported a colony-level NOAEC of 25 μg/kg (ppb) for imidacloprid and clothianidin. The toxicity of these insecticides to honeybees is however known to be reinforced with chronic exposure, and extrapolation of time-to lethal-effect toxicity plots compiled from published studies indicate that an imidacloprid level of 0.25 ppb, i.e. one-hundredth of the reported colony NOAEC, would kill a large proportion of bees nearing the end of their life.

Insects and insectivores on the brink of extinction in the Adirondacks

In September, the U.S. Fish and Wildlife Service denied a petition to put the Bicknell’s thrush (Catharus bicknelli) on the federal list of endangered species. The Bicknell’s is a medium-size (6-7.5 inches) thrush—brown on the back with a white, spotted underside—that dwells in dense balsam-fir forests in high elevations in the Adirondacks. Following is a primer on other wildlife in trouble in the Adirondack Park.

Paul Kirkland: How the plight of the butterfly may hit Scotland’s wild flowers

Much attention has been given to the plight of bees because of their importance as pollinators of major crops. But there is growing evidence that butterflies and moths – many of which have suffered dramatic declines in recent years – play an important role as specialist pollinators of some of our favourite wild flowers. A Swedish study recorded pollen on the bodies of three-quarters of butterfly species examined with some individuals carrying up to 350 grains.

Insect decline: the biodiversity of the entire world is at stake

Bees and butterflies are experiencing widespread population decline, creating public concern in recent years. Data collected in Germany suggest that it’s not just bees and butterflies at risk: insect populations overall have plummeted by more than 75 percent since 1989. Scientists have known about the population decline for several years. However, they didn’t know how many species were declining, and they didn’t expect it to be happening so fast.

UK will back total ban on bee-harming pesticides, Michael Gove reveals

The UK will back a total ban on insect-harming pesticides in fields across Europe, the environment secretary, Michael Gove, has revealed. The decision reverses the government’s previous position and is justified by recent new evidence showing neonicotinoids have contaminated the whole landscape and cause damage to colonies of bees. It also follows the revelation that 75% of all flying insects have disappeared in Germany and probably much further afield, a discovery Gove said had shocked him.

Onze landbouwgrond is zo dood als een pier

Het zijn niet alleen insecten en vogels boven de grond die last hebben van bestrijdingsmiddelen. In de bodem waar planten en gewassen groeien, werkt het gif net zo goed. Je hoort weinig over het bodemleven dat zich daar afspeelt. Maar het is essentieel. Miljoenen bacteriën, schimmels en allerlei andere bodemdiertjes, van aaltjes tot regenwormen, zorgen ervoor dat planten voedingsstoffen kunnen opnemen, dat er genoeg lucht in de bodem zit om gewassen te kunnen verbouwen en dat er voldoende gangetjes zijn waardoor de regen kan wegstromen.