Bijensterfte, oorzaken en gevolgen

Honeybees, bumblebees and many other insects are being slowly poisoned to death by persistent insecticides used to protect agricultural crops. Small doses of the toxic chemicals accumulate over time, meaning that there is no safe level of exposure. That’s the conclusion from recent research looking at the long-term effects of a commonly used class of insecticides.

Kamerbrief met antwoorden op Kamervragen over het gebruik van Merit Turf in openbare grasvegetatie en graszodenteelt, ter bestrijding van engerlingen en emelten. Volgens de minister zijn er geen onaanvaardbare risico’s. Bij de beoordeling van een middel wordt ook het risico voor het oppervlaktewater (aquatoxiciteit) meegenomen. Dat het middel is toegelaten betekent dat het risico voor in het water levende organismen volgens het Ctgb (College voor de toelating van gewasbeschermingsmiddelen en biociden) aanvaardbaar is. De relatie tussen de aanwezigheid van imidacloprid in het oppervlaktewater en bijensterfte is tot op heden niet aangetoond. Of er sprake zal zijn van een toename van imidacloprid in oppervlaktewater is op voorhand niet aan te geven. Dat is afhankelijk van het daadwerkelijke gebruik van het middel.

Zu den Warnungen des Bund für Umwelt und Naturschutz (BUND) und des Deutschen Berufsimkerbundes (DBIB) vor weiterem Bienensterben erklärt Ulrike Höfken, Sprecherin für Ernährungspolitik und Agrogentechnik: Die von BUND und DBIB vorgestellten Daten zeichnen ein erschreckendes Bild: Die Biene ist ein entscheidender Indikator für die durch Pestizide verursachten ökologischen Schäden. Es ist davon auszugehen, dass neben den gut dokumentierten Bienenvölkern zahllose andere Organismen durch die Neonicotinoid-Nervengifte geschädigt werden. Auch die Langzeitfolgen von Neonicotinoiden in geringer ("subletaler") Dosis sind bisher nicht untersucht. Die Bundesregierung schaut tatenlos zu. Sie hält an ihrer "weiter so"-Strategie fest und hat 2010 sogar Clothianidin wieder zugelassen, obwohl unabhängige Studien die Bienengefährlichkeit bestätigen.

Valent U.S.A. Corporation has received additional EPA registrations for Belay® Insecticide in a growing list of fruit, vegetable and nut crops. New registrations for Belay include use in pecans and other tree nuts, cranberries, peaches, and a number of vegetables, such as brassica, tuberous, corm, cucurbit, fruiting and leafy vegetable crops. California, New York and Florida registrations for these crops are pending. Valent also recently announced registrations for new foliar uses of Belay in cotton and soybeans for the 2010 season. Belay is a third-generation neonicotinoid containing clothianidin.

The UK Government and retailers are under pressure to impose a ban on sale of pesticides linked to bee population decline following new research which groups call a 'growing body of evidence'. Environmental groups including the Soil Association and Buglife are making a renewed call for an end to the use of neonicotinoid pesticides, which are among the most commonly used pesticides worldwide, after a new study linked them to a decline in bee populations.

A new study shows that due to a flaw in standard risk assessments, which consider toxic effects at fixed exposure times, the risks posed by the neonicotinoid pesticides imidacloprid and thiacloprid are likely to be underestimated. The authors believe that minute quantities of imidicloprid may be playing a much larger role in killing bees over extended periods of time than previously thought. The study, “The significance of the Druckrey–Küpfmüller equation for risk assessment—The toxicity of neonicotinoid insecticides to arthropods is reinforced by exposure time,” was published online July 23, 2010 in the journal Toxicology.

Vragen van het lid Jansen (SP) aan de minister van Landbouw, Natuur en Voedselkwaliteit over imidacloprid en thiacloprid in relatie tot bijensterfte (Ingezonden 2 augustus 2010)

Vragen van het lid Thieme (PvdD) aan de minister van Landbouw, Natuur en Voedselkwaliteit over nieuwe feiten omtrent de schadelijkheid van bestrijdingsmiddelen voor bijen. (Ingezonden 30 juli 2010). Thieme vraagt o.a. "Hoe beoordeelt u de conclusie dat langer durende blootstelling de giftige werking van neonicotinoide insecticiden versterkt en dat dit verklaart waarom ook zeer geringe hoeveelheden van deze stoffen in het milieu in de loop van de tijd een dodelijke werking op ongewervelde dieren, met daaronder ook bijen, hebben? Welke consequenties verbindt u daaraan?"

Neonicotinoid insecticides belong to the most important pesticides in the protection of agricultural crops. Honeybees may come into contact with them as a consequence of their wide-spread application. The first matter of investigation of this thesis dealt with a possible exposure route of honeybees towards neonicotinoid insecticides, focusing on the detection and quantification of neonicotinoids in the guttation liquid of maize plants cultivated from neonicotinoid-treated seeds using LC-MS/MS. The investigated neonicotinoids clothianidin, imidacloprid and thiamethoxam were detectable in the guttation liquid in considerable quantities in the ppm range. In the context of the possible exposure of honeybees to neonicotinoid insecticides these pesticides might be transferred into honey which represents a food with very high purity demands by consumers. In this context the main objective of this thesis was the development and validation of an analytical method for the simultaneous determination of neonicotinoid insecticides in honey and the subsequent analysis of Austrian honey and nectar samples.

De werkzame stoffen imidacloprid en thiacloprid hebben langer een negatief effect op de gezondheid van bijen dan gedacht.

Thu, Jul 22, 2010, Paul Tukey, safelawns.org
It’s been almost exactly three years since some impulsive research led me to David Hackenberg. I had just watched an advertisement for grub control for lawns and the punchline stated that “one application lasts 12 months.”

Compulsively suspect of chemical pesticides, I cringed when I thought of a substance that would persist in the soil for a year. “How can that possibly be a good thing?” I said aloud to my wife before she wandered off to bed with her omnipresent here-he-goes-again expression. “I wonder what the active ingredient is?” I asked to an empty livingroom.

Abstract
The essence of the Druckrey–Küpfmüller equation dt^n = constant(where d = daily dose and t = exposure
time-to-effect, with n>1) for chemical carcinogens is that the total dose required to produce the same effect decreases with decreasing exposure levels, even though the exposure times required to produce the same effect increase with decreasing exposure levels. Druckrey and Küpfmüller inferred that if both receptor binding and the effect are irreversible, exposure time would reinforce the effect. The Druckrey–Küpfmüller equation explains why toxicity may occur after prolonged exposure to very low toxicant levels. Recently, similar dose–response characteristics have been established for the toxicity of the neonicotinoid insecticides imidacloprid and thiacloprid to arthropods. This observation is highly relevant for environmental risk assessment. Traditional approaches that consider toxic effects at fixed exposure times are unable to allow extrapolation from measured endpoints to effects that may occur at other times of exposure. Time-to-effect approaches that provide information on the doses and exposure times needed to produce toxic effects on tested organisms are required for prediction of toxic effects for any combination of concentration and time in the environment.

Source: Henk A. Tennekes, The significance of the Druckrey–Küpfmüller equation for risk assessment—The toxicity of neonicotinoid insecticides to arthropods is reinforced by exposure time, Toxicology, in press,
doi:10.1016/j.tox.2010.07.005

Trouw, 8 juli 2010

De bijensterfte is dit jaar niet afgenomen. Van de bijenvolken die imkers houden bleek dit voorjaar 23 procent niet meer te leven. Vorig jaar was dat 22 procent. Dat meldt de Nederlandse Bijenhouders Vereniging.

US Agriculture Secretary Tom Vilsack announced that disaster assistance will be issued starting today to livestock, honeybee and farm-raised fish producers that suffered losses in 2008 because of disease, adverse weather or other conditions. Vilsack said. “The assistance announced today will be particularly helpful to beekeepers whose bees suffered from Colony Collapse Disorder (CCD) and will also assist other producers facing economic challenges.”

De sterke afname van bijen en andere bestuivers kan de Britse economie voor 440 miljoen pond (529 miljoen euro) schaden.

Vragen van het lid Polderman (SP) over Merit Turf in relatie met bijensterfte en vervuiling van oppervlaktewater
Ingediend 14 juni 2010

1. Klopt het dat op 04-06-2010 heeft het Ctgb besloten Merit Turf imidacloprid (13321) toe te laten in openbare grasvegetatie en graszodenteelt, ter bestrijding van engerlingen en emelten http://www.ctb.agro.nl/?

Ministerie van Landbouw, Natuur en Voedselkwaliteit
11 juni 2010 - kamerstuk

Geachte Voorzitter,

Hierbij stuur ik u de antwoorden op de vragen van het lid Thieme (PvdD) over bijensterfte en niet aangepaste zaaimachines.

Concerned US Agriculture Department officials on Monday announced the start of an ambitious survey of honeybee colonies in California and a dozen other states. "There has been a disturbing drop in the number of U.S. bee colonies over the last few years, while the demand for commercial bee pollination services continues to grow," Agriculture Secretary Tom Vilsack said. California's almond crop alone requires more than 1.4 million colonies of bees annually, amounting to more than half of all bees in the United States. The survey of 320 apiaries, though, is not a census of the total bee population. Instead, it will focus on mortality and troublemakers. Specialists from the Agricultural Research Service and Pennsylvania State University will collect bees and debris from selected apiaries. An acutely detailed, 22-page set of instructions specifies every step of the operation. So far, scientists have not identified a single cause for the population decline. Potential culprits include new microbes or viruses, pesticides and environmental stress. Agriculture Department scientists say cell phones aren't a problem, despite earlier speculation.

Stefano MAINI, Piotr MEDRZYCKI, Claudio PORRINI, Bulletin of Insectology 63 (1): 153-160, 2010

The impact of pesticides on honey bees is an issue that has been studied for many years and is now being reconsidered because controversy still exists with the relationship of insecticides and Colony Collapse Disorder (CCD). It is insufficient to explain CCD with only bee pathology studies. Research must be conducted on a wider series of causes: i) in open field and agroecosystems, to understand the fate of pesticide blends, ii) in the hives, to determine ways to enhance honey bee defence to diseases and parasites. References regarding imidacloprid and CCD in the maize agroecosystems are critically reviewed. Pesticides and the thechniques to rationally use them (in particular following the integrated pest management guidelines) represent one of the several puzzles regarding the mystery of CCD or honey bee vanishing. An appendix, i.e., a rejected letter to Science and relevant reply, is also reported.

Full paper: http://www.bulletinofinsectology.org/pdfarticles/vol63-2010-153-160maini...

Die Bienen sind in Gefahr und mit ihnen die ganze Artenvielfalt und die Bestäubung der Blüten, die wiederum Voraussetzung dafür ist, dass sich Früchte entwickeln können. Ohne Bienen kein Obst und kein Gemüse – die fleißigen Insekten leisten weit mehr für die Gesellschaft als nur deren Versorgung mit leckerem Honig. "Wir hatten herbe Völkerverluste zu beklagen", sagte Ralf Albert, Vorsitzender der Bonndorfer Imker, rund 50 Prozent der Bienenvölker hätten den Winder nicht überlebt, in manchen Regionen gingen die Verluste sogar bis 90 Prozent.

Het College voor de toelating van gewasbeschermingsmiddelen en biociden (Ctgb) heeft in de vergadering van 26 mei besloten tot de toelating van het middel Merit Turf op basis van de werkzame stof imidacloprid. Het middel mag worden toegepast als insectenbestrijdingsmiddel in openbare grasvegetatie en graszodenteelt, ter bestrijding van engerlingen en emelten.

bron: Ctgb, 27/05/10

ProRail en de stichting Natuur en Milieu gaan samen de strijd aan tegen de bijensterfte. De spoorbeheerder is met de bermen langs 6500 kilometer spoor één van de grootste natuurbeheerders in ons land. Spoorbermen zijn ideale plekken voor bijen om te leven. Om de samenwerking kracht bij te zetten plaatsen ProRail en Natuur en Milieu komende zaterdag een bijenhotel op het dak van NS-station Leiden.