Bijensterfte, oorzaken en gevolgen

Western culture views insects and arachnids as pests and vermin that need to be controlled. They usually are not considered as something to be preserved. Accordingly, arthropods and other small organisms have not been taken seriously for conservation by policy makers and the conservation community at large. Arthropods, however, are major components of diverse ecosystems and are the major players in functioning of ecosystem processes. Arthropods are relentlessly vanishing before our eyes. They must be preserved because of their inherent values but also because we need them for human survival.

PULLMAN, Washington, July 29, 2009 (ENS) — A microscopic pathogen and pesticides embedded in old honeycombs are two major contributors to the bee disease known as colony collapse disorder, which has wiped out thousands of beehives throughout the United States and Europe over the past three years, new research at Washington State University has confirmed.

Fri, Jul 17, 2009

Having received more than 12,000 comments from concerned citizens, the Environmental Protection Agency announced yesterday it will begin reviewing the pesticide responsible for Colony Collapse Disorder of bees.

As one of the first organizations in the U.S. to begin tracking this story, SafeLawns.org has long concluded that a synthetic nicotine known as imidacloprid — used to kill grubs on lawns — is responsible for the widespread bee epidemic that has claimed more than a third of the nation’s beehives since 2006. France, Germany, Italy and several other nations have already banned the chemical, often marketed as “Merit,” that has been licensed for use in the U.S. since the 1990s, but came into widespread use in 2005 after the EPA banned diazinon.

[updated 4 December 2009] In the Netherlands, a petition to ask for measures to stop honeybee decline started in June 2009. In five months time, 40856 citizens have signed the petition. The petition has been delivered to the parliament on November 24, 2009. The text of the petition is:

The Netherlands is not the only country that started a petition to ask policy makers to take measures to stop honeybee decline. The UK Soil Association has started a petition calling on the Government to protect honeybees and ban neonicotinoid pesticides. See:
http://www.soilassociation.org/Takeaction/Savethehoneybee/tabid/434/Default.aspx

The text of the petition is:
We, the undersigned support the Soil Association in calling on Hilary Benn, the UK’s Secretary of State for Environment, Food & Rural Affairs to ban neonicotinoid pesticides with immediate effect. These pesticides have been shown to kill honeybees and are thought to be a contributory factor in the recent dramatic increase in honeybee deaths.

In a briefing paper the background of the petition is explained.

New research by Prof. Vincenzo Girolami of the University of Padova in Italy shows Neonicotinoids in maize kill bees via water droplets. The same seed-dressed imidacloprid maize as the one used in this experiment is widely grown in the Netherlands.

Here you can see a video clip of the effects:

By Thad Box - www.WesternFarmerStockman.com June 2009 - opinion

It is generally accepted that toxic bank loans caused our financial system to collapse. Now it appears that toxic substances are causing collapse of a whole host of pollinators that keep natural systems functioning efficiently. And the collapses of both the financial and biological systems are part of a larger system failure. Beginning in the 1990s, beekeepers began to suspect the systemic insecticide imidacloprid for death of bees. This is a product that is taken up by plants and becomes systemic, that is it is stored in and moves through the plant system. Once the chemical is in the nectar and pollen of the plant, nothing can protect pollinators who gather the poisoned food.

June 16, 2009 Press Association Newsfile, Emily Beament, Press Association Environment Correspondent

Honeybees are making a comeback to Kew Gardens today as part of a campaign to encourage people to grow bee-friendly flowers in their gardens.

Lynda MacGibbon, 12 June 2009, canadaeast.ca

The bee was the size of an adult's thumb and strong enough to nudge the screen door open an inch or two. It was big enough to scare a scream from my housemate, Ashley, whose unhappy childhood encounter with a bee perhaps explains her anxious behaviour.

Eventually, between the two of them -- one screaming and opening the door, the other buzzing distractedly, the bee was freed. Ashley lived to tell the tale.

I should have more sympathy for Ashley. As a child she suffered her share of stings. But, truthfully, when it comes to bees, I'm in their corner. Humans can fend for themselves.

More wild flowers should be planted on derelict land, roadside verges and other public spaces to save honey bees, the Women's Institute believes.

The number of bumblebees in the UK has declined by around 70 per cent since the 1970s and honey bees by up to 15 per cent in the last two years, according go official Government figures.

The sudden decline in bees has been blamed on intensive farming techniques, climate change and a mysterious condition known as colony collapse disorder. It could cause serious problems for agriculture and food production since bees are essential to pollinate many plants.

Prof. Joe Cummins presents evidence that parasitic fungi can kill insects when low, otherwise non-lethal concentrations of pesticides are present

The neonicotinoid insecticides used to dress seeds are systematic, and accumulate in plant parts including the flowers. Hence honeybees collecting pollen will become exposed to the pesticide, and become more susceptible to fungal pathogens. The parasitic fungus, Nosema ceranae, a single celled parasite was indeed found in CCD-affected bee hives from around the USA.

Research conducted using only honey bees as the indicator species may not adequately reflect the risk posed by insecticides to wild bees because of their differential susceptibility and unique biology.

C.D. Scott-Dupree, L. Conroy, and C.R. Harris

ABSTRACT Pest management practices may be contributing to a decline in wild bee populations in or near canola (Brassica napus L.) agroecosystems. The objective of this study was to investigate the direct contact toxicity of five technical grade insecticides - imidacloprid, clothianidin, deltamethrin, spinosad, and novaluron - currently used, or with potential for use in canola integrated pest management on bees that may forage in canola: common eastern bumble bees [Bombus impatiens (Cresson); hereafter bumble bees], alfalfa leafcutting bees [Megachile rotundata (F.)], and Osmia lignaria Cresson. Clothianidin and to a lesser extent imidacloprid were highly toxic to all three species, deltamethrin and spinosad were intermediate in toxicity, and novaluron was nontoxic. Bumble bees were generally more tolerant to the direct contact applications > O. lignaria > leafcutting bees.
However, differences in relative toxicities between the three species were not consistent, e.g., whereas clothianidin was only 4.9 and 1.3x more toxic, deltamethrin was 53 and 68x more toxic to leafcutting bees than to bumble bees and O. lignaria, respectively. Laboratory assessment of direct contact toxicity, although useful, is only one measure of potential impact, and mortality under Þeld conditions may differ greatly depending on management practices. Research conducted using only honey bees as the indicator species may not adequately reßect the risk posed by insecticides to wild bees because of their unique biology and differential susceptibility. Research programs focused on determining nontarget impact on pollinators should be expanded to include not only the honey bee but also wild bee species representative of the agricultural system under investigation.

Daily Post (Liverpool) May 25, 2009, North Wales Edition

The Assembly Government has announced a pounds 486,000 boost for beleaguered Welsh honeybees.

(ANSA) - Rome, May 5 - Bees are repopulating northern Italy thanks to a ban on new types of pesticides believed responsible for decimating them, the Italian Beekeepers Association announced on Tuesday. UNAAPI Chairman Francesco Panella said the return of the bees in the fields of northern Italy ``proved that their decimation is directly linked to the ban on neonicotinoids``introduced by the agriculture ministry last September.

ScienceDaily (Aug. 20, 2008) — Honey bees industriously bring pollen and nectar to the hive, but along with the bounty comes a wide variety of pesticides, according to Penn State researchers. Add the outside assault to the pesticides already in the waxy structure of the hive, and bee researchers see a problem difficult to evaluate and correct. However, an innovative approach may mitigate at least some beeswax contamination.

The Associated Press, May 19, 2009 Tuesday

The decline of honeybee colonies has slowed slightly since last fall, but a mysterious combination of ailments is still decimating the insect's population, federal researchers say.

U.S. Department of Agriculture researchers found that honeybee colonies declined by 29 percent between September 2008 and early April. That's an improvement over the last two years, when researchers found that 32 percent and 36 percent of all beekeepers surveyed lost hives.

Aberdeen Press and Journal, May 20, 2009 Wednesday

DECLINING bee numbers is one of the "most worrying" environmental changes on the planet and will drastically hit food production, including Scotland's soft fruit output, if not reversed, according to a Highland MSP.

Labour MSP Peter Peacock said the decline of honey bees and other insects had been happening unnoticed and yet had profound implications for everyone.

It is estimated 84% of crops in the EU and 80% of wildflowers rely on insect pollination.

The Daily Yomiuri(Tokyo), May 19, 2009 Tuesday

The low buzzing of honeybees lingered on the sandbar in the middle of the Kisogawa river, on the border of Aichi and Gifu prefectures.

Workers wearing netting on their faces used bellows to blow smoke into the hives to calm the occupants, and quietly opened the beehives.

The Independent (London), May 18, 2009 Monday

By Martin Hickman, Consumer Affairs Correspondent

For decades, Britain's native black bee has been an outcast. The Victorians threw Apis mellifera mellifera out of hives in favour of more industrious foreign species. Modern beekeepers brand it lazy and aggressive.

Now, the nation's original honeybee is coming in from the cold. Scientists believe the insect that made honey for the tables of medieval kings could reverse the collapse of bee numbers that has imperilled the annual pollination of crops worth £165m.

Dutch summary: De voedingswaarde van stuifmeel (vooral het eiwitgehalte) beinvloedt de levensverwachting van bijen. Een te eenzijdig dieet van stuifmeel met een laag eiwitgehalte zou een rol kunnen spelen bij bijensterfte. Zie ook www.bieenkorf.be/bijensterfte.pdf voor Nederlandstalige informatie over deze factor.

Pollen Power
by: Joe Traynor, February 01, 2009

Not all pollens are created equal.

All beekeepers are aware that protein is a key constituent in a healthy bee diet – honey provides the carbohydrates, pollen supplies the protein. When it comes to pollen, though, not all pollens are created equal [1,2,3].

Nicolas Desneux, Axel Decourtye, and Jean-Marie Delpuech

Abstract
Traditionally, measurement of the acute toxicity of pesticides to beneficialarthropods has relied largely on the determination of an acute median lethal dose or concentration. However, the estimated lethal dose during acute toxicity tests may only be a partial measure of the deleterious effects. In addition to direct mortality induced by pesticides, their sublethal effects on arthropod physiology and behavior must be considered for a complete analysis of their impact. An increasing number of studies and methods related to the identification and characterization of these effects have been published in the past 15 years. Review of sublethal effects reported in published literature, taking into account recent data, has revealed new insights into the sublethal effects of pesticides including effects on learning performance, behavior, and neurophysiology. We characterize the different types of sublethal effects on beneficial arthropods, focusing mainly on honey bees and natural enemies, and we describe the methods used in these studies. Finally, we discuss the potential for developing experimental approaches that take into account these sublethal effects in integrated pest management and the possibility of integrating their evaluation in pesticide registration procedures.

Laura Bortolotti, Rebecca Montanari, José Marcelino2, Piotr Medrzycki, Stefano Maini,
Claudio Porrini

Abstract
For several years, reports by French and Italian beekeepers have been suggesting a lethal effect of imidacloprid on honey bees; in particular, the molecule has been related to honey bee mortality and decrease of hive populations, affecting the orientation and ability of honey bees to return to the hive.

Axel Decourtye, Eric Lacassie, Minh-Hà Pham-Delègu

Abstract: To establish the sublethal concentrations domain, acute and chronic oral tests were
conducted on caged honeybee workers (Apis mellifera L) using imidacloprid and a metabolite, 5-OHimidacloprid,
under laboratory conditions. The latter showed a 48-h oral LD50 value (153ng per bee)
five times higher than that of imidacloprid (30ng per bee). Chronic feeding tests indicated that the
lowest observed effect concentrations (LOEC) of imidacloprid and of 5-OH-imidacloprid on mortality

Axel Decourtye, James Devillers, Sophie Cluzeau, Mercedes Charreton and Minh-Hà Pham-Delègue

Abstract

E. C. Yang, Y. C. Chuang, Y. L. Chen, and L. H. Chang

Although sublethal dosages of insecticide to nontarget insects have never been an important issue, they are attracting more and more attention lately. It has been demonstrated that low dosages of the neonicotinoid insecticide imidacloprid may affect honey bee, Apis mellifera L., behavior. In this article, 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.

Figure 4: The ratio of missing bees after feeding on 50% sugar water containing different concentrations of imidacloprid.

Uitleg in het Nederlands: Het plaatje laat zien hoeveel procent van de bijen in het experiment van Yang na het snoepen van suikerwater met imidacloprid hun eigen volk niet meer terug konden vinden, althans, niet meer bij de kast terugkeerden. Hoe meer imidacloprid in het suikerwater werd gedaan (hoe verder naar rechts in het plaatje) hoe hoger het percentage bijen dat de weg naar de korf niet meer terug kon vinden, althans er niet meer aankwam.