We measured uptake and dissipation of soil-applied imidacloprid and dinotefuran in nectar and leaves of 2 woody plant species, a broadleaf evergreen tree (Ilex attenuata) and a deciduous shrub (Clethra alnifolia), to assess concentrations to which pollinators and pests might be exposed in landscape settings. Three application timings, autumn (postbloom), spring (prebloom), and summer (early postbloom), were evaluated to see if taking advantage of differences in the neonicotinoids’ systemic mobility and persistence might enable pest control while minimizing transference into nectar.
Dat hebben onderzoekers van de universiteit van Texas (Austin) ontdekt. Ze stelden honingbijen bloot aan glyfosaat, het actieve bestanddeel van Roundup. Drie dagen later reeds bleken de bijen behoorlijk wat goede bacteriën in hun darmen kwijt te zijn geraakt. Met name de bacterie Snodgrassella alvi werd hard geraakt. Deze bacterie is heel belangrijk voor de bijen, omdat deze ze helpt om voedsel te verwerken en zich tegen ziekteverwekkers te beschermen.
Bees living in suburban habitats are still being exposed to significant levels of pesticides despite the EU ban on the use of neonicotinoid pesticides on flowering crops, new research from University of Sussex scientists shows. The study, with colleagues at Stirling University and Rothamsted Research, found that neonicotinoid exposure for rural bumblebees declined after the ban's implementation in 2015 but the risk to bumblebees in suburban gardens remained largely the same.
New research reveals that hummingbirds and bumble bees are being exposed to neonicotinoid and other pesticides through routes that are widespread and complex. The findings are published in Environmental Toxicology & Chemistry. To measure exposure to pesticides in these avian pollinators, investigators made novel use of cloacal fluid and fecal pellets from hummingbirds living near blueberry fields in British Columbia. They also collected bumble bees native to Canada, and their pollen, and blueberry leaves and flowers from within conventionally sprayed and organic blueberry farms.
Irish bumblebee populations recorded in 2017 were at the lowest since monitoring began six years ago, with marked losses in critical native species, according to the latest monitoring figures. The declines are confirmed by the All-Ireland Bumblebee Monitoring Scheme co-ordinated by Dr Tomás Murray, senior ecologist at the National Biodiversity Data Centre in Co Waterford.
Pesticides can act as endocrine disrupting chemicals (EDCs) in animals providing characteristic multiphasic dose-response curves and non-lethal endpoints in toxicity studies. However, it is not known if neonicotinoids act as EDCs in bees. To address this issue, we performed oral acute and chronic toxicity studies including concentrations recorded in nectar and pollen, applying acetamiprid, clothianidin, imidacloprid, and thiamethoxam to bumble bees, honey bees and leafcutter bees, the three most common bee species managed for pollination.
Most Britons remain blithely unaware that since the Beatles broke up, we have wiped out half our wildlife. Yet we are not alone. Last week, the French woke up in a dramatic way to the fact that their own farmland birds, their skylarks and partridges and meadow pipits, were rapidly disappearing: Le Monde, the most sober of national journals, splashed the fact across the top of its front page.
Die als Insektenbekämpfungsmittel eingesetzten Neonicotinoide sind für Bienen schädlich – so viel scheint klar. Doch einige Mittel aus dieser Substanzklasse wirken viel toxischer als andere. Warum das so ist, haben nun Forscher aufgeklärt. Demnach sind die Insektizide besonders schädlich, die zusätzlich zu ihrer Giftwirkung auch bestimmte Abwehrenzyme der Bienen hemmen. Dadurch können die Insekten das Gift nicht mehr abbauen, bevor es Schaden anrichtet.
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).