Bijensterfte, oorzaken en gevolgen

28-Jan-2010, Helmholtz Association of German Research Centres
A first-time overview of the population trends for honey bee colonies and beekeepers in Europe

Cardiff/Halle/S./Bern. The number of bee colonies in Central Europe has decreased over recent decades. In fact, the number of beekeepers has been declining in the whole of Europe since 1985. This is the result of a study that has now been published by the International Bee Research Association, which for the first time has provided an overview of the problem of bee colony decline at the European level. Until now there had only been the reports from individual countries available. As other pollinators such as wild bees and hoverflies are also in decline, this could be a potential danger for pollinator services, on which many arable crops depend, according to what an international team of scientists have written in a special edition of the Journal of Apicultural Research.

[New study by Alaux et al, 2010, Biology Letters]

ABSTRACT
The maintenance of the immune system can be costly, and a lack of dietary protein can increase the susceptibility of organisms to disease. However, few studies have investigated the relationship between protein nutrition and immunity in insects. Here, we tested in honeybees (Apis mellifera) whether dietary protein quantity (monofloral pollen) and diet diversity (polyfloral pollen) can shape baseline immunocompetence (IC) by measuring parameters of individual immunity (haemocyte concentration, fat body content and phenoloxidase activity) and glucose oxidase (GOX) activity, which enables bees to sterilize colony and brood food, as a parameter of social immunity. Protein feeding modified both individual and social IC but increases in dietary protein quantity did not enhance IC. However, diet diversity increased IC levels. In particular, polyfloral diets induced higher GOX activity compared with monofloral diets, including protein-richer diets. These results suggest a link between protein nutrition and immunity in honeybees and underscore the critical role of resource availability on pollinator health.

NEW YORK, New York, January 4, 2010 (ENS) – A pesticide approved just 18 months ago must be taken off the market because it could be toxic to America's honey bees, already in steep decline.

Nationally, there are three main reasons for the loss of wildlife on farmed land: 1. Farming has become more specialised. Historically most farms were a mix of grassland and different arable crops. 2. Farming has become much more intensive, with increased applications of fertiliser and pesticides. Herbicides and insecticides reduce numbers of wild plants and insects, thus reducing the food supply for other wildlife, such as birds and mammals. 3. Habitats have been lost through conversion to other land uses, agricultural intensification or through inappropriate or lack of management.

New research has shown that Europe’s farmland birds have declined by almost 50% in the past 25 years – a trend caused by EU-wide agricultural intensification being driven by a policy in need of urgent reform. The results bring together the most comprehensive biodiversity indicators of their kind in Europe, collated by the Pan-European Common Bird Monitoring Scheme (PECBMS) - a partnership led by scientists from the European Bird Census Council, BirdLife International, the RSPB (BirdLife in the UK) and Statistics Netherlands.

The September 2009 issue of The Internationalist presents in seven articles a comprehensive discussion on the vanishing bees.

With almost one million described species, insects eclipse all other forms of animal life on Earth, not only in sheer numbers, diversity, and biomass, but also in their importance to functioning ecosystems. However, human-induced changes to the natural environment threaten vast numbers of these organisms and the vital services they provide to ecosystems. Leading causes of insect endangerment are habitat destruction or alteration of habitat by chemical pollutants (such as pesticides). Pesticides are implicated in the decline of many native bees and some aquatic insects.

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.