Honeybees

Fipronil blamed for historical bee deaths

Researchers in the UK report new evidence that the pesticide fipronil, not the neonicotinoid imidacloprid, caused a massive die-off of honey bees in France from 1994 to 1998. Both pesticides hit the market in the early 1990s. At the time, beekeepers and environmentalists largely blamed imidacloprid for the bee deaths. Now, Philippa Holder and colleagues at the University of Exeter and Fera Science, a UK public-private venture focused on agricultural science, suggest that fipronil used on sunflowers was more likely the culprit (Proc. Natl. Acad. Sci. U.S.A.

Imidacloprid Found to Make Bees Less Social

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.

Neonicotinoid Residues in Nectar and Foliage of Systemically Treated Woody Landscape Plants

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.

Glyfosaat blijkt indirect bij te dragen aan de sterfte onder bijen

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.

Bee losses in Virginia over the winter nearly 60 percent

Winter losses of honeybee colonies over the 2017-2018 season were greater than expected and greater than the average of 30 percent per year for the past decade. “The winter losses were 59.5 percent,” said Keith Tignor, Virginia State Apiarist. He adds that this is the highest rate since 2000 when the state began monitoring winter losses. There was a decrease in colony losses reported for the summer of 2017 when compared to the 2016 summer season. VDACS staff found high levels of Varroa mites and nosema infections in wintering bees.

The importance of time-to-effect experiments rather than fixed-duration studies for evaluating chronic toxicity

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.

‘Neonicotinoïden ook verbieden in kassen’

Neonicotinoïden veroorzaken onherstelbare schade bij insecten, zegt toxicoloog Henk Tennekes. “Bayer is aansprakelijk voor de massale insectensterfte die imidacloprid heeft veroorzaakt.” De EU verbood eind april de neonicotinoïden clothianidin, imidacloprid en thiamethoxam voor gebruik in buitenteelten. Toxicoloog Henk Tennekes van adviesbureau Experimental Toxicology Services (ETS) Nederland vindt dat de EU het verbod moet uitbreiden naar kassen. Volgens Tennekes komen de giftige stoffen vanuit de kassen terecht in het oppervlaktewater.

Neonicotinoids may affect the developing nervous system of children

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.

Neonicotinoids act like endocrine disrupting chemicals in newly-emerged bees and winter bees

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.