Insecticides

Luxemburg muss Fortschritte in Sachen Wassermanagement machen, so das Fazit der Debatte in der Chamber am Donnerstag. Dabei ging es nicht nur um die Geldbuße, die das Großherzogtum aus Brüssel aufgebrummt bekommen hat, sondern auch um den Umgang mit dem Juli-Hochwasser und der Verschmutzung der Flüsse, wie sie dieses Jahr auf Attert und Alzette aufgetreten ist. Die Abgeordneten diskutierte lange, welche Aufgaben Luxemburg noch bewältigen muss.

Last month, a frog died in an Atlanta botanical garden. With it went an entire species never to hop along the Earth again. Biologists at Zoo Atlanta who’d looked after the frog for the past 12 years called him “Toughie.” He was a charismatic, glossy-eyed specimen and the very last Rabbs’ fringe-limbed tree frog in the world. Joseph Mendelson, the director of research at Zoo Atlanta, had been prepared for this. When the Rabbs’ frog was discovered in Panama in 2005, some 80 percent of the population had already been lost to disease. A few were removed in hope of a revival.

Forty years ago, swallows were a common sight in the summer, darting between the beams of old barns or swooping low over the waters of a creek. These swift aerial acrobats seemed to be everywhere -- perched on telephone lines by the dozen awaiting the fall migration, or whirling and diving around old wooden bridges in pursuit of airborne insects. Now, these birds have seemingly disappeared from midair, entirely abandoning large swathes of their former Canadian range. Some, like the bank swallow, have seen their numbers plummet by 98 per cent since 1970.

This study measured part of the in-hive pesticide exposome by analyzing residues from live in-hive bees, stored pollen, and wax in migratory colonies over time and compared exposure to colony health. We summarized the pesticide burden using three different additive methods: (1) the hazard quotient (HQ), an estimate of pesticide exposure risk, (2) the total number of pesticide residues, and (3) the number of relevant residues. Despite being simplistic, these models attempt to summarize potential risk from multiple contaminations in real-world contexts.

This thesis by Sebastian Stehle analyses the agriculture–environment linkages for pesticides at the global scale and it thereby contributes to a new research frontier in global ecotoxicology. The overall findings substantiate that agricultural insecticides are potential key drivers for the global freshwater biodiversity crisis and that the current regulatory risk assessment approaches for highly toxic anthropogenic chemicals fail to protect the global environment.

The evaluation of pesticide side-effects on honeybees is hampered by a lack of colony-level bioassays that not only are sensitive to physiological changes, but also allow predictions about the consequences of exposure for longer-term colony productivity and survival. Here we measured 28 biometrical, biochemical and behavioural indicators in a field study with 63 colonies and 3 apiaries. Colonies were stressed in early summer by feeding them for five days with either the carbamate growth regulator fenoxycarb or the neurotoxic neonicotinoid imidacloprid, or left untreated.

High brown Fritillary butterfly - Once widespread it is now reduced to around 50 sites and threatened with extinction; Great Crested Newt – a sharp decline with only around 75,000 existing across the country; Hen Harrier – One of Britain’s most threatened birds of prey with only around 600 breeding pairs left; Hazel Dormouse – declined by one third in recent years and it is not extinct in 17 counties; Barbastelle Bat – widespread decline and fewer than 5,000 remaining; Ringed plover – only 5,600 breeding pairs remaining; Water vole – populations have dropped by 90 per cent in recent years;

In Deutschland gibt es immer weniger Bienen, immer weniger Hummeln, immer weniger Schmetterlinge. Überhaupt gibt es immer weniger Insekten! Das haben Forscher aus Krefeld herausgefunden. Das ist eine Stadt im Bundesland Nordrhein-Westfalen. 25 Jahre lang haben die Forscher an bestimmten Orten Insekten gesammelt, ihre Art bestimmt und die Tiere gewogen. Das Ergebnis der Forscher: In dieser Zeit stellten sie einen Rückgang an Insekten von bis zu 80 Prozent fest. Gesammelt haben die Forscher vor allem in Nordrhein-Westfalen.

Neonicotinoid insecticides like thiacloprid enter agricultural surface waters, where they may affect predator-prey-interactions, which are of central importance for ecosystems as well as the functions these systems provide. The effects of field relevant thiacloprid concentrations on the leaf consumption of Gammarus fossarum (Amphipoda) were assessed over 96 h (n = 13-17) in conjunction with its predation on Baetis rhodani (Ephemeroptera) nymphs. The predation by Gammarus increased significantly at 0.50-1.00 microgram/L.