Honeybees

Scientists said they’ve found that exposure to the neonicotinoid pesticide imidacloprid produces complex changes in the social behaviors and activities of bumblebees – a very bad thing for creatures who rely on their colonies to survive. Bumblebees exposed to imidacloprid became less social and spent less time together. The bees also spent less time nursing larvae, foraging and constructing the wax canopy which insulates and regulates the temperature of the hive.

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.

Synthetic fungicides are pesticides widely used in agriculture to control phytopathogenic fungi. The systemicity, persistency and intense application of some of these fungicides, such as boscalid, leads to long periods of exposure for honeybees via contaminated water, pollen and nectar. We exposed adult honeybees in the lab to food contaminated with boscalid for 33 days instead of the standard 10-day test. Most of the toxic effects were observed after 10 days.

Two popular types of the pesticide neonicotinoid used widely on America’s foods may cause brain impairment and should be restricted, according to a recent study by a team of European scientists. Researchers from the European Food Safety Authority (EFSA) recommended further restrictions on the use of neonicotinoids in the wake of new data which indicate that the class of pesticides "may affect the developing human nervous system" of children.

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.