Insecticides

De tulpen worden duur betaald

In 2008 is in 40% van alle metingen van imidacloprid in het oppervlaktewater van het bloembollenteelt areaal een overschrijding gevonden, veruit het hoogste percentage sinds de start van de metingen in 2001. Overschrijdingen vinden vooral plaats in het ‘Noord-Hollands Zandgebied’ (57% van de metingen) en ‘Noord-Hollands Kleigebied’ (56%), beide in het gebied van het Hoogheemraadschap Hollands Noorder Kwartier (HHNK). Dit zijn de gebieden met het grootste areaal tulp, waarin het middel veel wordt ingezet. In de meetperiode 2003-2004 is imidacloprid voor het eerst in het meetnet bollenteelt normoverschrijdend aangetroffen. De hoogste gemeten concentratie van het voor bijen zeer giftige insecticide imidacloprid lag in 2005 meer dan 24000x boven de norm en in 2006 meer dan 15000x boven de norm. De bollenteelt concentreert zich in Nederland op zandgrond, dat zeer kwetsbaar is voor uitspoeling. Uit een recent RIVM rapport (bijlage) blijkt dat in de bollenteelt de hoeveelheid imidacloprid die in het oppervlaktewater terecht komt vooral bepaald wordt door drainage (ontwatering). Drainage is strikt noodzakelijk omdat een constant grondwaterpeil voor bollenteelt (bijvoorbeeld tulpen) zeer belangrijk is. De verantwoordelijkheid voor oppervlaktewaterverontreiniging met imidacloprid door de bollenteelt kan dus niet op de bollenboeren worden afgeschoven.

Anything but pesticides!

Could the commercial interests of pesticide companies be affecting the impartiality of researchers? Bee researchers at Italy’s University of Bologna certainly think so. “Despite the fact that CCD is unanimously considered by scientists to depend on several causes, two camps are now in conflict,” they write in “The puzzle of honey bee losses” (Maini, Bulletin of Insectology 63:153-60). “On the one side are the environmentalists/beekeepers and on the other pesticide companies and the scientists sponsored by them." Attached is an article on the influence of Bayer Cropscience on Dutch policy makers (which appeared in the magazine "Vrij Nederland" on April 4, 2012).

Ecological effects of imidacloprid in experimental rice fields

Ecological changes caused by the insecticide imidacloprid were monitored in experimental paddies throughout a cultivation period. A total of 88 species were observed, with 54 of them aquatic. Plankton, nekton, benthic, and terrestrial communities from imidacloprid fields had significantly less abundance of organisms compared with control fields, either for the entire period or during early stages. The absence of Chironomus yoshimatsui and typical paddy ostracods from imidacloprid fields was most remarkable; as a consequence, green algae blooms (Spirogyra sp.) developed, which in turn hampered the establishment of weeds. Such changes occurred while residues of imidacloprid in water were present at levels greater than 1 μg/L. The overall diversity was similar in all fields and increased constantly until the end of the study. Phytophagous insects dominated in early communities, gradually giving way to predators and scavengers during late stages, but imidacloprid fields had a lower proportion of the latter trophic group. Multivariate analyses helped to describe and differentiate the communities between treatments and control. Hazard- and risk-assessment methods failed to predict imidacloprid impacts, probably because of deficiencies in the exposure and relevant toxicity data used.

Bee poisoning with neonicotinoids coinciding with the corn sowing period in Austria

In 2009 35 beekeeping operations from 6 federal provinces of Austria reported incidents of suspected bee poisoning to the Institute for Apiculture of the Austrian Agency for Health and Food Safety (AGES). For 33 of these operations beekeepers expressed the suspicion of an bee poisoning incident. The appearance of honey bees with symptoms of poisoning coincided to a high degree with the corn sowing period.

Manfred Hederer (Präsident des Verbands der Berufsimker): „Der Todeskampf der Honigbiene und der Imkerei in Deutschland hat begonnen“

In diesen Tagen blühen die ersten Kirschbäume, verströmen ihren Duft. Doch das Summen der Bienen, die damit angelockt werden sollen, dürfte vielerorts ausbleiben: Honigbienen-Sterben hat je nach Region „bis zu 80 Prozent der Völker vernichtet“, berichtet die „Deutsche Bundesstiftung Umwelt“ (DBU). Besonders betroffen sind die neuen Bundesländer, aber auch Teile Bayerns, Niedersachsens, Nordrhein-Westfalens und das Saarland. Manfred Hederer (58), Präsident des Verbands der Berufsimker (DBIB) und mit fast 60 Prozent Verlustquote selbst Geschädigter: „Viele von uns kämpfen nach diesem Horrorwinter um ihre Existenz, etliche Hobby-Imker denken ans Aufhören.“

Neonicotinoid insecticides implicated in honeybee mass poisoning incidents

An investigation by Buglife – the Invertebrate Conservation Trust has revealed that there is evidence of an increasing link between neonicotinoid pesticides and bee deaths in Britain. Buglife reviewed data from Fera, the Government’s agricultural research organisation, (attached) and found that there have been several cases in the last two years when the Wildlife Incident Investigation Scheme has implicated neonicotinoid pesticides in mass bee deaths. Not only that, but the number of reported incidents have been rising in recent years and, importantly, an increasing proportion of the incidents are associated with neonicotinoid pesticides.

Toxikologe Henk Tennekes: „Wenn die Insekten verschwinden, kollabiert das Ökosystem"

Die Suche nach Ursachen für das Bienensterben zeigt: Manche Feinde sind vom Menschen gemacht. Ganz oben auf der Liste stehen sogenannte Neonicotinoide. Dazu gehören Mittel wie Clothianidin, Imidacloprid oder Thiamethoxam – Nervengifte zur Schädlingsbekämpfung. Der niederländische Toxikologe Henk Tennekes hat ein Buch zu diesem Thema veröffentlicht.

Seine Studien beschreiben die Wirkung von Nervengiften auf Insekten: „Sie binden sich an Rezeptoren im zentralen Nervensystem und diese Bindung ist nahezu irreversibel, ist unumkehrbar.“ Ist die Chemie der wahre Verursacher des Bienensterbens?

Jeff Pettis: Bee decline in the US 'not explained by pesticides'

A leading American bee researcher, Dr. Jeff Pettis, who first posed a link between insecticides called neonicotinoids and bee deaths told British MPs in April 2011 that his research doesn't explain bee losses seen in the US (presentation and study report attached). "The lab study certainly seemed very clear that low levels of pesticides were impacting on honey bee health. But when we look in the field we don't see the same results. Even when colonies that were exposed to low levels we're not seeing outbreaks of the gut parasite pathogen that we saw in the lab" said Dr Jeff Pettis of the US Agricultural Research Service. The video interview with Jeff Pettis is at this link http://bcove.me/fyyb68e7

Abnormal Foraging Behavior Induced by Sublethal Dosage of Imidacloprid in the Honey Bee (Hymenoptera: Apidae)

The foraging behavior of the honey bee workers was investigated to show the effects of imidacloprid. By measuring the time interval between two visits at the same feeding site, we found that the normal foraging interval of honey bee workers was within 300 s. However, these honey bee workers delayed their return visit for >300 s when they were treated orally with sugar water containing imidacloprid. This time delay in their return visit is concentration-dependent, and the lowest effective concentration was found to be 50 μg/liter. When bees were treated with an imidacloprid concentration higher than 1,200 μg/liter, they showed abnormalities in revisiting the feeding site. Some of them went missing, and some were present again at the feeding site the next day. Returning bees also showed delay in their return trips. Our results demonstrated that sublethal dosages of imidacloprid were able to affect foraging behavior of honey bees.