Hommels

Mierenlokdoosjes, vliegenstrips en andere producten waarin bepaalde insecticiden zitten, blijven te koop. De Tweede Kamer had op initiatief van de Partij voor de Dieren aangedrongen op een verkoopverbod aan particulieren van de bestrijdingsmiddelen die gevaarlijk zijn voor bijen en hommels. Daarvoor bestaat geen grondslag, zo heeft staatssecretaris Wilma Mansveld (Milieu) aan de Kamer geschreven. Ze baseert zich daarbij op onderzoek van het College voor de toelating van gewasbeschermingsmiddelen en biociden (Ctgb). Volgens het college zijn de risico's van middelen met zogeheten neonicotinoïden voor bijen en mensen verwaarloosbaar. In een reactie schrijft de toxicoloog Henk Tennekes dat het Ctgb bij de beoordeling van imidacloprid de wettelijke kaders waaraan het Ctgb gebonden is heeft overtreden. Imidacloprid voldoet aan geen van drie in de Nederlandse wetgeving opgenomen milieucriteria waaraan de toelaatbaarheid van een gewasbeschermingsmiddel getoetst dient te worden (persistentie in de bodem, uitspoeling naar het grondwater, en de risico’s voor waterorganismen). Staatssecretaris Mansveld heeft met haar adviesaanvraag aan een incompetente instantie het primaat van de politiek de facto afgegeven aan Nefyto, de belangenorganisatie van de agrochemische industrie in Nederland, aldus Tennekes.

Aufregung herrscht derzeit unter den Imkern im Raum Deutsch Jahrndorf (Bez. Neusiedl). Dutzende Bienenvölker sind tot. Die betroffenen Imker glauben, dass das Bienensterben nach wie vor auf das Konto von Schädlingsbekämpfungsmitteln geht. Es sieht schlimm aus in den Bienenkästen. Einer der Betroffenen ist der Bio-Imker und ehemalige Landesobmann der burgenländischen Bienenzuchtvereine Konrad Schneider aus Deutsch Jahrndorf. „Ich habe 60 Völker auf den Ständen in Nickelsdorf, Deutsch Jahrndorf und Pama verloren. Auch andere Imker sind betroffen, mein Nachbar hat 30 verloren“, erklärt Schneider.

We are delighted to welcome you to Charles Darwin House for the “The Impact of Pesticides on Bee Health” – the third joint meeting between the three societies. The Biochemical Society, the British Ecological Society and the Society for Experimental Biology have a long history of organizing and supporting meetings on all aspects of biochemistry, cell biology and ecology. We believe this joint meeting between the societies (to be held at the joint headquarters of the three societies) will succeed in bringing together experts from around the world, who are solving biological problems using multiple integrated approaches. The final video discussion session can be viewed on Youtube at a http://www.youtube.com/watch?v=6pbCGDWed68.

Many people have read about the decline of the honeybee in the news in recent years. Experts agree that a combination of changes in habitat, exposure to pesticides, mites, disease, and other factors have harmed them. But less attention is paid to wild bees and other pollinators, which are also extremely important.

Honeybees are not native to North America. Records indicate they were brought over by English settlers in the 1600s for honey and wax. But there have always been native bees and other pollinators who did the work of pollination before honeybees arrived and still do much of that work today. Pennsylvania has 300 different species of wild bees, alone. The honeybee is useful to us. They alone provide delicious honey and we need them for pollinating some of the cultivated landscapes we require to feed ourselves. Honeybees are considered to be the most valuable pollinators in agriculture, because they are well understood, relatively easy to maintain, movable, and able to communicate rapidly the locations of new food sources. Some crops are almost entirely dependent on the honeybee for production. Blueberries and cherries are 90-percent dependent and almonds almost entirely.

Ein neues Paper von Hannah Feltham, Kirsty Park und Dave Goulson aus der Arbeitsgruppe von Prof. Goulson (Univ. Essex) zeigt, dass die Effizienz der Pollensammeltätigkeit bei Hummeln durch Imidacloprid massiv beeinträchtigt wird; und das schon bei Konzentrationen von 6 ppb (Pollen) und 0.7 ppb (=µg/kg) Imidacloprid im Trinkwasser. Leider spricht das Papier manchmal inkorrekt von "doses", statt von "concentrations", und liefert damit wieder unnötige Angriffspunkte für Kritik. Die Konzentrationen wurden "Feld-realistisch" gewählt, orientiert an Konzentrationsmessungen von Prof. Bonmatin in Pollen und Nektar von Raps (aus Imidacloprid-gebeiztem Saatgut). Diese Konzentrationen liegen im sublethalen Bereich.

By courtesy of Tom Theobald, Boulder County Beekeepers, here are ‘animated’ maps constructed from USGS pesticide usage maps up until 2009, (now 4 years old). You can see how the use of clothianidin (given illegal conditional registration in 2003) has spread.
Imidacloprid
http://www.bouldercountybeekeepers.org/animation-imidacloprid.html

Clothianidin
http://www.bouldercountybeekeepers.org/animation-clothianidin.html

Thiamethoxam
http://www.bouldercountybeekeepers.org/animation-thiamethoxam.html
Each reveals, in a dramatic manner, how the use of just three of the neurotoxic chemicals has spread across the American landscape since 1993.

Bumblebees and other pollinators provide a vital ecosystem service for the agricultural sector. Recent studies however have suggested that exposure to systemic neonicotinoid insecticides in flowering crops has sub-lethal effects on the bumblebee workforce, and hence in reducing queen production. The mechanism behind reduced nest performance, however, remains unclear. Here we use Radio Frequency Identification (RFID) technology to test whether exposure to a low, field realistic dose (0.7 ppb in sugar water and 6 ppb in pollen) of the neonicotinoid imidacloprid, reduces worker foraging efficiency. Whilst the nectar foraging efficiency of bees treated with imidacloprid was not significantly different than that of control bees, treated bees brought back pollen less often than control bees (40 % of trips vs 63 % trips, respectively) and, where pollen was collected, treated bees brought back 31 % less pollen per hour than controls. This study demonstrates that field-realistic doses of these pesticides substantially impacts on foraging ability of bumblebee workers when collecting pollen, and we suggest that this provides a causal mechanism behind reduced queen production in imidacloprid exposed colonies.

Neonicotinoid insecticides are a relatively new, but widely-used, class of systemic, water-soluble nerve poisons. They are readily incorporated into all plant cells, as well as pollen and nectar. They act by binding to acetylcholine receptors of plant-feeding insects, inducing depolarization of motor neurons, tetanic contractions, neuromuscular destruction and death. Non-target plant-feeding insect groups (e.g., bees, certain moths and butterflies) exposed to these insecticides are at risk. Declines in these insect groups are well documented, while noting that these declines can be attributed to habitat loss and invasive species as well as to pollution from neonicotinoid insecticides and other agricultural chemicals. In many agricultural areas, populations of animals that rely on plant-feeding insects as food sources (e.g., birds, bats, amphibians, predatory insects) are also declining.