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.
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 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.
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.
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).
Since 2007 honey bee colony failure rates overwinter have averaged about 30% across much of North America. In addition, cases of extremely rapid colony failure have been reported, which has been termed colony collapse disorder. Both phenomena result from an increase in the frequency and intensity of chronic diseases and environmental stressors. Colonies are often challenged by multiple stressors, which can interact: for example, pesticides can enhance disease transmission in colonies.