Bee deaths

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The word dieback is used in a variety of ways, as a catchphrase and as a technical term.

In public debates and in the media, the buzzword bee deaths stands for the thesis that there is a sharp decline in the number or density of colonies of the Western honeybees ( Apis mellifera ) worldwide , for which humans are affected by globalized, industrial-technical forms of land use (monocultures , Pesticides, transport etc.) and which has fatal consequences for food production due to a lack of pollination by bees . This view is also conveyed in well-known films such as Vanishing of the Bees (2009), The Secret of Bees Dying (2010) and More than Honey (2012). However, the honey bee is seen as a special case by researchers, as it is used commercially and is therefore heavily dependent on the beekeeper - the rule is that it cannot become extinct as long as there are beekeepers.

However, an analysis of the population development of globally managed bee colonies cannot support the thesis that global bee deaths are caused in this way; rather, there are very different findings of increases and decreases in the density of bee colonies across regions and regions. These findings can be partly explained by socio-economic changes that have made beekeeping attractive or unattractive for beekeepers. In some cases, bee colony losses could be traced back to clear causes, for example the new appearance of introduced parasites such as the varroa mite , or, in two cases, improper use of neonicotinoids as seed dressings . In many other cases, especially in cases of increased winter mortality, as a syndrome also known as colony collapse disorder , mostly abbreviated to CCD , sole causes have not yet been scientifically proven. Rather, there is a need for further research into the combination of several factors.

As a technical term, bee mortality refers to wild bees , of which more than 50% of German wild bee species are on the Red List of Endangered Species . The wild bees are not considered in the following article. In the broadest sense, the term bee deaths is used as a synonym and catchphrase for insect death.

Colony Collapse Disorder

Colony Collapse Disorder ( English , shortly CCD ) is a from the United States derived term for a particular form of bee mortality. Symptoms are the rapid loss of adult workers in the hive and the lack of dead workers in and around the hive. Brood, young bees, honey and pollen, however, are still present. Nest pests and kleptoparasitism also occur only with a delay.

Development of the bee populations

The FAO has annually compiled official estimates of the number of commercial beehives in many countries since the early 1960s. That number has increased or decreased in many countries over the past 50 years. In the United States, it fell from 5.5 to 2.6 million between 1961 and 2014. In India it rose from 5 to 11.6 million in the same period, in China from 3.2 to 8.9 million. In Germany, the number of beehives fell from 2 to 0.7 million, in Turkey it rose from 1 .5 to 6.6 million

Overall, the number of commercial beehives increased by approx. 45% between 1961 and 2007, according to FAO information. While the number fell in North America (-49.5%) and Europe (-26.5%), it increased in Asia (+426%), Africa (+130%), South America (+86%) and Oceania (+ 39%). There were also considerable divergences within the regions; for example, the number increased significantly in Finland, Canada and Spain, while it decreased in Germany, Sweden and the USA.

history

“The death of bee colonies is part of nature and beekeeping culture. Winter loss rates of 10% of the stock have been in effect since documentation began at the end of the 19th century. than normal. ”The buzzword bee deaths relates to the significantly higher winter losses and significant losses of bee colonies, also during the season, observed for several decades.

North America

United States

In autumn 2006, individual beekeepers in the USA suffered massive losses that were greater than the usual annual winter losses. Such massive losses occurred in the 1880s, 1920s and 1960s, although it is unclear whether these were CCDs. Other unusual cases of bee deaths have also been observed in the past. In 1903, 2000 beehives disappeared in Utah's Cache Valley after a severe winter and cold spring. In the winter of 1995–96, Pennsylvania lost 53 percent for no apparent cause.

In 1853, Lorenzo Langstroth reported about beehives that were found empty one morning. In 1891 and 1896, large numbers of bees disappeared in what was described as May disease . In the 1960s, bees disappeared in Texas, Louisiana, and California. A similar epidemic occurred in 27 states in 1975, and again in California in 2005.

The Bee Informed Partnership, a joint project between leading US research laboratories and universities with support from the US Department of Agriculture (USDA) , has been collecting data on honey bee losses every year since 2006. This data is collected in the form of surveys of beekeepers, in which the beekeepers provide information, among other things, on the number of beehives at different times of the year, increases and decreases in this number, as well as the causes of losses assumed by the beekeepers. The nationwide winter losses averaged 29% over the previously published data from ten winters. In the first survey winter 2006-07 the losses were 32%, in the most recent survey winter 2015-16 they were 28%. The losses differ significantly between individual states, seasons and husbandry forms.

A study published in 2015 (Lee et al., 2015) analyzed the data from the 2013–14 survey winter. Garden and part-time beekeepers had higher, commercial beekeepers lower relative losses. The scientists involved in the analysis of the survey suggest that the lower losses of commercial beekeepers can be attributed to the fact that, unlike hobby beekeepers, they usually transport their hives to warmer regions in winter and also treat them against the varroa mite. The results also showed in all years that beekeepers who transport their beehives and use them to pollinate almond trees experience similar or lower losses than beekeepers who do not. The most common causes of winter losses cited by beekeepers in annual surveys were queen failure, varroa mite , starvation, autumn weakness, pesticides, poor winter conditions and CCD. For the winter of 2013-14, garden beekeepers (96% of those surveyed) and part-time beekeepers (2.6%) cited poor winter conditions, starvation and autumn weakness as the most common causes. Commercial beekeepers (1.4%) named failure of the queen (approx. 20% of those surveyed) as well as varroa mites (approx. 16%) and pesticides (approx. 14%) as the most common causes for the same year (similar to 2012–13).

According to a study published in 2015 based on the data from the survey winter 2014–15 (Seitz et al., 2015), the causes of winter mortality cited by smaller beekeepers are mainly management problems (e.g. starvation, autumn weakness), while larger commercial beekeepers in primarily identified parasites or factors beyond their control (e.g. varroa, nosema, queen failure).

Canada

As part of the COLOSS research project, surveys were carried out on winter losses 2009-10 in Canada. Losses ranged from 16% to 25% in six provinces, with losses being particularly high in Nova Scotia .

A research project carried out in southern Ontario collected data from more than 400 randomly selected beehives between 2007 and 2008. The winter loss rate was 27%. Of the factors examined, the varroa mite infestation was most strongly associated with losses.

Europe

In Europe, the number of honey bee colonies decreased from over 21 million (1970) to 15.5 million (2007). This decline was slow until 1990, and then significantly steeper. Since there are no area-wide annual surveys in Europe - unlike in the USA - developments and fluctuations are more difficult to determine; for some countries data are missing or are estimated by the FAO. No consistent developments can be identified between different countries, for example the number of honey bee colonies in Germany has increased slowly since 2000, still lower than in 1961, while the number in France is higher today than in 1961, but has been decreasing since 2000.

The Europe-wide research network COLOSS (Prevention of honey bee COLony LOSSes) was launched in 2008 and has since developed internationally standardized survey protocols on the basis of which representative and internationally comparable surveys on forms of beekeeping, bee losses and possible risk factors are carried out. In winter 2012–13, the winter losses and risk factors recorded in this way were analyzed in 18 northern, central and western European countries as well as Israel. 16.1% of the overwintering beehives were lost. The losses fluctuated considerably between countries and beehive stocks of different sizes, from less than 10% in Bosnia and Herzegovina to high losses of over 30% in Scotland and Ireland. Regarding the risk factors, a regression analysis shows that the keeping conditions of the honeybees are important, such as the type of treatment against the varroa mite and the detection and correction of problems in the queens. In addition, access to certain agricultural crops (maize, rape) increases the risk of death for honeybees (although it has not been clarified whether this environmental factor is related to the type of habitat, the nutritional value of the crops or the treatment with pesticides).

As part of the EPILOBEE research project, bee mortality in 2012–13 and 2013–14 in 17 EU countries was investigated using representative random samples from apiaries and apiaries. There were considerable divergences in mortality between the two years and different countries. The highest winter mortality was recorded in Belgium in 2012–2013 (31.73%) and the lowest in Lithuania in 2013–2014 (2.16%). A hierarchical cluster analysis found the highest winter mortality (14.04%) among hobby beekeepers over 65 years of age with small apiaries that produced queens and have little experience in beekeeping. The lowest winter mortality (8.11%) was observed for professional beekeepers between the ages of 30 and 45 who operate large and migrating apiaries. The professional beekeepers had higher qualifications, training and experience in beekeeping; their bees did not suffer from diseases. In a statistical analysis of the factors responsible for higher bee mortality, the variables varroaose, lack of training, non-use of a beekeeping book and non-participation in veterinary treatment were significant. Another study published in March 2017 based on the same data also found a decisive influence of professional beekeeping on bee mortality.

Germany

The Varroa mite (here on the body of a honey bee) is one of the main causes of increased winter losses in Germany.

In Germany there were unusually high losses averaging 30% in the winter of 2002–03, with many beekeepers suffering much higher losses and many other beekeepers much lower losses. No simple explanation could be found for this phenomenon. As a result, the German bee monitoring project was launched in autumn 2004, the aim of which was to clarify the causes of higher winter losses. To this end, 1200 beehives in 120 apiaries were observed over several years and extensive data on viral, bacterial and fungal pathogens, varroa infestation, the health status and strength of the beehives at different times of the year, mite treatments, proximity to certain crops, pesticide residues in rape pollen (the most important Source of nectar and pollen for bees in late spring) as well as keeping conditions collected by professional bee inspectors and the beekeepers themselves. Mortality rates were then examined with the help of correlation analyzes. The average winter losses observed between 2004–05 and 2007–08 were between 4% and 15%. The causes of winter losses identified in the study are 1) high mite infestation, 2) infections in autumn with the wing deformation virus , 3) infections in autumn with the acute bee paralysis virus , 4) old queens, and 5) weak beehives before winter. The main cause of the wintering problems is undoubtedly the infestation with the Varroa mite. An effect of pesticide residues on mortality could not be determined, whereby the study design was not designed to record sublethal and chronic effects of multiply polluted pollen. For this, more extensive sampling and further investigation methods are necessary. In the context of the monitoring, mainly residues of pesticides that are classified as non-toxic for bees were found in amounts three orders of magnitude below the corresponding LD50 dose . As various studies have shown harmful effects of pesticides on honey bees, more research is needed.

The analysis of pesticide residues in pollen (bee bread) carried out as part of the DeBiMo was the first study of this type in Germany. On the basis of data from several years up to and including 2010, no connection between pollen contamination and colony development or winter losses could be demonstrated. A relatively large number of samples were contaminated, but in most cases the values ​​were in the low range and well below the respective LD50 values. Although no direct bee-toxic concentrations were detected, the evidence of the cocktail of pesticide residues in pollen gave reason to investigate the combinatorial and chronic effects of the substances on bee colonies. Targeted experiments are necessary for this.

German bee monitoring has been funded by the federal government since 2010. For the three-year funding period 2011–2013, average winter losses of 9.9% (2010/2011), 13.3% (2011/2012) and 13.3% (2012/2013) were determined, with a clear variability between beekeepers and regions . As in previous years, there was a significant correlation between the varroa mite infestation and the loss rates and also with the wing deformation virus. Other viruses and nosemas could not be linked to losses. There was also no direct connection for residues of pesticides in bee bread; Above-average arrears did not result in any increased loss rates. The final report for the 2014–2016 funding period is currently in progress, and the 2017–2019 funding period has been applied for.

Criticism of NGOs on German bee monitoring

In January 2011, BUND and NABU published a joint press release in which, based on an assessment by Happe and Safer (2011), they accused the DeBiMo of methodological deficiencies that would prevent a correct determination of the contribution of pesticides to bee mortality.

The German Bee Monitoring responded that, unlike activists, it had approached the investigation of the causes with an open mind and rejected the criticism.

Asia

As part of the COLOSS research project, surveys were carried out on winter losses in 2009-10 in China and Turkey. These showed low losses averaging 4% in China and moderate losses of 26% in Turkey.

Between 2010 and 2013, around 3,000 beekeepers in China were surveyed using the COLOSS method in order to collect data on loss rates and risk factors. Overall, winter losses were small (10.1% average), but fluctuated significantly with the year and the province. The lowest losses (8.5%) were found in winter 2012–13, the highest in 2011–12 (12%). Commercial beekeepers (> 200 bee colonies) tended to suffer higher losses with an annual average of 12.1% than part-time beekeepers (50–200 bee colonies) with 8.9%. In Xinjiang (19%) and Henan (16.2%) the losses were significantly higher than in all other provinces (<10%). The study estimated the potential impact of risk factors using a generalized linear model . Beekeepers who renewed their honeycombs more frequently, according to the results, had lower losses because new honeycombs are free of pathogens, parasites or chemical contaminants, thus reducing the risk of disease. A higher proportion of beehives that had problems with their queens was associated with higher losses.

Africa

South Africa

Pirk et al. (2013) examined the losses in the years 2009–10 (29.6%) and 2010–11 (46.2%) using a survey of 48 beekeepers. Migrating beekeepers had higher losses (35.5%) than sedentary ones (17.2%). Beekeepers whose bees pollinated certain crops (apples, eucalyptus, onions, sunflowers) recorded higher losses than others. Cape bee keepers had lower losses (17.9%) than East African highland bee keepers (29.1%). The beekeepers questioned named the small hive beetle , varroa mites, fleeing the beehive and lime brood as causes for losses .

causes

The causes of bee deaths are not yet fully understood. The most important cause of bee deaths in the United States, Germany and Switzerland is the varroa mite infestation . In addition, factors such as diseases, malnutrition, genetic engineering, management and insecticides are examined. A study published in 2019 with international participation sees the high losses of recent times in the combination of neonicotinoids and the infestation with the varroa mite.

Infestation by the varroa mite

The main cause of bee deaths in Germany is varroosis, i.e. the infestation of the bee colonies by the varroa mite . The parasite Nosema , pesticide residues and other suspected causes, on the other hand, were of little consequence according to the results of the long-term study "German bee monitoring" published in early 2011, which was coordinated by the Working Group of Institutes for Bee Research . The authors write that the results of the long-term analysis can also be transferred to other regions of Europe and possibly parts of North America. However, the statements of this study are heavily criticized by many beekeepers and environmental organizations such as NABU and BUND . The use of pesticides was not investigated at all. It is viewed as critical that "50 percent of the project was borne by the industry (BASF, Bayer and Syngenta)", which produced the controversial pesticides.

In Switzerland, too, the varroa mite is a major factor in bee deaths.

“... the mite Varroa destructor - it is by far the most important cause of bee deaths. All bee colonies in Switzerland are infected with this parasite and, if left untreated, a colony dies within a year or two. Even if suitable measures are taken, it is not certain that the sick bees will survive - because weakened individuals and colonies are usually infected by viruses in addition to the mites, which ultimately leads to the death of a colony. "

- Bee researcher Prof. Peter Neumann in January 2013

Colonies with younger queens apparently have significantly higher chances of wintering. Other factors can increase the mite's harmfulness. The mites could transmit viruses or the injuries caused could promote secondary infections.

Disturbance of protein production

According to recent research results, protein production is disturbed in all of the bee colonies affected. It is believed that this disorder is caused by picornaviruses , which are transmitted, among other things, by varroa mites. The disturbed protein production also makes the bees more susceptible to other harmful environmental influences.

Parasite Apocephalus borealis

An Apocephalus borealis female lays her eggs in the abdomen of a worker bee.
Two Apocephalus borealis larvae leave their host worker bee at the junction of the head and thorax.

According to a 2012 study by San Francisco State University , the humpback fly Apocephalus borealis is another cause of bee deaths in the United States. Accordingly, the females of this species lay their eggs in the bees, whereupon the bees fly around without any sense of direction and leave the hive at night. How exactly the infection works is still unclear. The flies have already been detected in California and South Dakota.

Malnutrition or malnutrition

When CCD appeared, all of the dead bee colonies examined in a study had previously suffered from “exceptional stress”, mostly from a lack of food and / or drought. Accordingly, there is a possibility that the phenomenon is related to diet-related stress and does not occur in healthy, well-fed bee colonies.

Some researchers brought the bees dying with the feeding of corn syrup (English: high fructose corn syrup , HFCS) to supplement the winter supplies in conjunction. Differences between corn syrup from different sources could explain the discrepancies in their research. However, if that were the only factor, then CCD would only occur in overwintering beehives that were fed corn syrup. However, there have been numerous reports of other cases of CCD in which beekeepers did not use corn syrup.

In this context, the type of beekeeping that is common in the USA must also be explained. There are many beekeepers there with several hundred colonies of bees. For the commercial pollination of crops, bee colonies are transported across the country to huge monocultures that provide only very one-sided nourishment. Both the long journeys of the bee colonies and the potential malnutrition of monocultures are stress factors that could promote bee deaths.

More recent results suggest that the increase in carbon dioxide in the earth's atmosphere due to the burning of fossil fuels encourages bee deaths. Higher CO 2 concentrations in the atmosphere lead to a decrease in protein values and thus in nutritional value in many crops , which is also true for certain important pollen suppliers such as B. the Canadian goldenrod applies. As a result of the CO 2 increase from 280 to 398 ppm between 1842 and 2014, protein declines of around one third were found in this; That the increase in CO 2 was the cause was then experimentally confirmed in the laboratory by tests with various CO 2 levels between 280 and 500 ppm. Since pollen is the only source of protein for bees, it can weaken bees' health and lead to colony deaths.

Pesticides

Protest against neonicotinoids at the demonstration We're sick of it! 2013.

One of the more common general hypotheses states that CCD is caused by the use of pesticides and their improper application. Initially, no common environmental factors could be found in studies of several, unrelated outbreaks. The hypothesis, long strongly advocated by environmentalists and beekeepers, that such pesticides should be seen as the main cause of bee deaths, was difficult to verify for several reasons:

  1. Due to the large number of pesticides used, it is hardly possible to test for all conceivable pesticides at the same time.
  2. Numerous professional beekeeping companies are highly mobile and transport their hives over long distances in the course of a season, whereby the bee colonies can be exposed to a different pesticide mixture at each location.
  3. The bees themselves store both pollen and honey for longer periods. Accordingly, it can take days and months before the potentially contaminated material is finally fed to the colony, so that in these cases it is impossible to link the onset of symptoms to a time when the hive came into contact with certain pesticides . In any case, there was no improvement in the mortality of bee colonies in France, although the use of “gaucho” on maize and sunflowers has been banned there since 1999 at the insistence of beekeepers.

When used as seed dressing in large parts of Europe today, the substances in question are classified as not dangerous for bees anyway , since no effects have been demonstrated so far.

Pesticides on the forage plants visited by bees are far more likely to get into the hive with the pollen than through the nectar , because the pollen is transported outside of the bee, but the nectar inside, so that the bee dies if it is too toxic. However, many potentially lethal substances, whether natural or artificial, do not act on the adult bees at all, but primarily on the brood. In the case of CCD, the brood does not seem to be affected. Significantly, the brood is not fed honey, while adult bees consume very little pollen. The fact that adult bees die (or disappear) with CCD symptoms suggests that any environmental pollutants or toxins are most likely to be found in honey.

So far, most of the evaluation of the possible involvement of pesticides in CCD has been based on studies submitted by beekeepers. Many beekeepers affected by the CCD report that they used antibiotics and acaricides (against mites) in their hives . So far, however, there has been no evidence of a single active ingredient that could be considered a trigger for CCD. In principle, the symptoms observed by beekeepers, such as disorientation and inexplicable changes in behavior, can certainly speak in favor of pesticides as the cause of the CCD, since pesticides, especially insecticides from the neonicotinoid group , act as neurotoxins . These include Acetamiprid , Clothianidin , Nitenpyram , Thiacloprid , Thiamethoxam and Imidacloprid . The latter is used as a "gaucho" in around 120 countries around the world with an annual turnover of over 500 million euros.

A 2010 review for the United States found honey bees to be highly exposed to varroacides used in the beehive and pesticides used in agriculture. It is known that chronic exposure to neurotoxic insecticides and these in combination with other pesticides, especially fungicides , are harmful to bees. A direct connection with CCD and decreased health of bees needs further research. The same applies to the dangers of neonicotinoids when bees are exposed to them in low doses. Although no single pesticide can in itself be attributed to causing CCD, synergistic effects of several pesticides may contribute to damage to the health of bees. Here too, the authors state that there is a need for further research. The study itself states that the decline began immediately after the introduction of dichlorodiphenyltrichloroethane (DDT) in agriculture and has continued unabated since then.

When thousands of bee colonies died in April / May 2008 in the Rhine Valley , the neonicotinoid clothianidin used as a seed dressing was clearly proven to be the cause . As a result, on May 15, 2008 , the Federal Office for Consumer Protection and Food Safety stopped the sale and use of initially eight seed treatment products, but the entire group of neonicotinoids - including a product from Bayer CropScience called "Poncho" - which contain this active ingredient, was raised the suspension of the approval of four seed dressings on June 25, 2008 after the agents were modified.

According to a study published in March 2012, these pesticides lead in the smallest, non-lethal doses in a significant way to a misorientation and workers can no longer find their way to the home beehive.

The product "Gaucho" manufactured by Bayer , which is based on the neonicotinoid imidacloprid, has been under suspicion for years after a study by the French government in 2003 showed that imidacloprid can kill bees under certain conditions. In 2012, biologists at Harvard University published a study that found a direct link between imidacloprid and CCD. 15 out of 16 (94%) of the bee colonies observed died within 23 weeks, although some of them were exposed to very low doses.

At the end of April 2013, 15 of the 27 EU member states , including Germany, decided to partially ban three controversial pesticides from the neonicotinoid group ( clothianidin , imidacloprid and thiamethoxam ) in the cultivation of maize, sunflower, rapeseed and cotton for an initial period of two years . Austria's Agriculture and Environment Minister Nikolaus Berlakovich , among others, voted against the ban . The final decision lies with the EU Commission , which advocates a ban. According to an EASAC opinion published in April 2015, there is a debate over whether honeybee colonies are affected by neonicotinoids. However, this overlooks the fact that the colonies are often very resistant to losses.

An EFSA opinion on clothianidin , imidacloprid and thiamethoxam published on February 28, 2018 finally confirmed the risks for wild and honey bees in field applications. This report is the basis for further approval decisions or restrictions. On April 27, 2018, the EU Commission voted to ban the use of these three active ingredients in outdoor crops. As early as May 5, 2018, 20 fields near Udine were confiscated because of bee deaths caused by pesticides. Their harvest is also destroyed.

According to a study published in September 2018 by Nancy Moran's group , glyphosate affects the intestinal microbiota of young honey bees by inhibiting the shikimic acid pathway in bacteria of the species Snodgrassella alvi and thereby killing them. As a result, a weakening of the resistance to harmful bacteria was observed.

In Switzerland there was massive bee deaths in 2019 because pirimicarb from the Landi was contaminated with fipronil .

The previous ecotoxicological risk assessments of pesticides were found to be inadequate by researchers. In order to counteract the sixth mass extinction in history, the risk assessments for chemicals must be reformed as soon as possible.

Pathogens and immunodeficiency

Another main cause is infection with certain viruses in the winter months. Some researchers pointed out that the pattern of spread resembled that of an infectious disease ; however, there is also evidence of a possible connection with an immunodeficiency , similar to AIDS in humans, possibly in connection with the above-mentioned stresses that weaken the immune system. Specifically, according to the group's researchers at Pennsylvania State University, "The level of infectious material found in adult bees suggests immune system impairment." The researchers also pointed to a possible link between varroa mite infection and CCD: It could be that a combination of mite infestation, the Deformed Wing Virus transmitted by them and a bacterial infection leads to a failure of the immune system and could be a cause of CCD. This research group is reportedly focused on looking for possible viral or bacterial pathogens as well as fungal infections. According to more recent findings (September 2007), the Israel Acute Paralysis Virus (IAPV ), which was first identified in 2004, is another possible secondary infection of varroosis: A research team from Pennsylvania State University has examined samples from healthy and CCD-infected beehives and from China for three years imported royal jelly and apparently healthy bees from Australia. With the help of a new, fast genome sequencing technique, they were able to record all the microorganisms that can be found in honey bees. In the course of the statistical analysis of all data, they found a connection between CCD and an organism called Israeli Acute Paralysis Virus.

Investigations from 2008 by the Canadian biologists Otterstatter and Thomson ( University of Toronto ) showed a connection with the pathogen Crithidia bombi (flagellates from the class of Kinetoplastea ), which occurs mainly in bees and bumblebees used to pollinate food vegetables such as cucumbers or tomatoes . The biologists found an increased number of Crithidia pathogens in wild bees and bumblebees that lived close to the greenhouses . A computational model of the distribution of the Crithidia when hymenoptera escaped from greenhouses came into contact with their wild relatives showed exactly the epidemic-like increase in the number of cases observed in the United States.

Another theory suggests that some beekeepers may not have been able to identify known bee diseases such as foulbrood or nosemosis as such. The infection of western honey bees with Nosema ceranae , a previously indistinguishable from the classic pathogen, but apparently more virulent Nosema species, which was detected in Europe for the first time in Spain at the end of 2005 , was linked by some researchers to the rampant bee deaths in Spain. The symptoms described are very reminiscent of CCD. In the United States, however, no infectious diseases were found in studies of affected colonies and it is therefore currently considered very unlikely that CCD is caused by known (and now easily diagnosable) bee diseases, especially since their classic symptoms are different from those of CCD.

When a colony perishes while other, healthy colonies are nearby (as is usually the case in beekeeping operations), the healthy colonies invade the hive of the dying colony to steal its supplies. If the supplies of the dying colony were contaminated with natural or man-made toxins, the resulting pattern of previously healthy colonies becoming ill in the vicinity of a dying colony would create the impression of a contagious disease. However, in cases of CCD, it is often reported that the supplies of dying tribes are not being stolen. This suggests that a contagious factor may not be involved in CCD.

Transgenic Plants

A link between Bt maize and CCD has been suggested by research in Germany. A study carried out by the University of Jena between 2001 and 2004 examined the effects of Bt maize pollen on bees. In general, a chronic toxic effect of Bt maize of the varieties Bt176 and Mon810 on healthy honey bee colonies could not be demonstrated. When the bee colonies were infested with parasites (microsporidia) in the first year of the study, significantly more bees that received pollen with Bt toxins as food died. An interaction of the toxin and pathogen on the epithelial cells of the honeybee's intestine is assumed. No differences were found when the bees were given a prophylactic antibiotic. The Jena study has not yet been published in a specialist journal and could not be replicated .

Canadian scientists found no effect of pollen from Bt maize on bee mortality. Mexican scientists could not find any effect of various syrups with Cry1Ab protein on bee colonies. A thousand times the dose of Cry3b contained in pollen produced no toxic effects on bee larvae, and feeding honey bees with pollen from Cry1Ab maize had no effect on survival rate, intestinal flora, or the development of the hypopharyngeal glands in which the protein-rich food for the brood is found is produced from. A meta-analysis published in 2008 of 25 independent studies on the effects of Bt toxins on honeybee mortality found no negative effects of the currently approved transgenic plants on the survival rates of larvae or adult bees.

According to a review by Peggy G. Lamaux, there is no evidence in the scientific literature that supports the hypothesis of direct or indirect damage from approved transgenic plants. In addition, only a small proportion of the protein intake of bees consists of pollen. Finally, there is also a lack of geographical correlation between the cultivation of transgenic plants and the occurrence of CCD. For example, there was CCD in Switzerland, where no cultivation takes place.

Cellular

In 2005 and 2006, in studies by the educational informatics working group at the University of Koblenz-Landau, base stations of inexpensive cordless DECT telephones were installed directly in the bottom of the hive of bees to investigate pulsed electromagnetic radiation . Negative effects on the finding and learning behavior of flying bees in the test colonies could be determined. DECT technology (frequencies, modulation) is also approximately comparable to mobile radio technology . However, this experimental set-up should primarily provide evidence that honey bees are suitable as so-called bioindicators for such electromagnetic radiation with low energy (below a thermal effect) and secondarily show the effect on the learning behavior of the bees. The studies did not aim to determine a possible cause of CCD. A study carried out in 2009 and published in 2011 by Daniel Favre, a former biologist at the ETH in Lausanne, showed clear connections between the activity of mobile phones and an increased buzzing of bees, which is interpreted as a sign of stress. The experiment was carried out 83 times. After every 20 to 40 minutes of irradiation, the intensity of the humming of the bees increased nine-fold. This can lead to many bees leaving the hive.

Importance for agriculture

By far the most important contribution the honeybees make to modern agriculture is their pollination capacity . 22.6% and 14.7% of agricultural production in developing and industrialized countries are directly dependent on pollination by honey bees. The global value of insect pollination has been estimated at € 153 billion, which is 9.5% of agricultural production. The EU25 accounts for € 14.2 billion and North America including Mexico for € 14.4 billion. Honey bees are not the only or most efficient pollinators, but collectively they are the most important ones for most monocultures worldwide. Domesticated honey bee colonies are ideally suited for this work, as they have a large number of workers all year round and, as generalists, pollinate a wide range of flowering plants, their populations can be increased at short notice by additional feeding and they can be transported over large distances with standardized systems .

Crops that do not rely on animal pollination represent the majority of human caloric intake. The share of these plants in the global arable land has decreased in the last 50 years in favor of animal-pollinated plants (which tend to be more economically valuable). As a result, the demand for pollination services is increasing, while the supply of honeybee colonies is growing more slowly. Loss of all pollinators would result in an estimated 3–8% decline in global agricultural production. Such productivity losses would lead to an expansion of the arable land in order to continue to meet global demand, which would have negative ecological consequences.

Alleged quote from Albert Einstein

In connection with the bee deaths, a statement is often quoted that is said to come from Albert Einstein :

“When the bees disappear, man has only four years to live; no more bees, no more plants, no more animals, no more people. "

According to Jerry Bromenshenk, a bee researcher at the University of Montana in Missoula and a member of the American CCD Working Group, an inquiry at the Einstein Institute in Israel revealed that the quote was not from Einstein.

According to journalist Hannah Nordhaus, the sentence first appeared in a brochure that was distributed during a political protest by French beekeepers in 1994 against the high cost of sugar for bee feed and a possible reduction in import tariffs on honey. She also pointed out that people in history have lived without honeybees in many areas (e.g., in North America before the arrival of the English in 1620) and that much of agricultural production does not require pollination by bees.

Films and novels

A number of cinema and television films on the subject of bee deaths have been produced in recent years, for example Vanishing of the Bees (2009), The Secret of Bees Dying (2010) and More than Honey (2012).

The novel The Story of the Bees by Maja Lunde also takes place against the backdrop of bee deaths.

The Black Mirror television series also covered the issue of bee deaths. The sixth episode of the third season deals, among other things, with built bee endrons that perform the same task as bees and are intended to serve as a replacement when bees die.

Web links

Wiktionary: Bee deaths  - explanations of meanings, word origins, synonyms, translations

See also

Individual evidence

  1. ↑ Honey in the head. In: zeit.de. May 20, 2018, accessed September 10, 2019 .
  2. ↑ Moritz, RF 2014: The causes of global bee deaths. In: Roundtables of the Commission for Ecology 43: 87–94, here 87.
  3. ↑ Moritz, RF 2014: The causes of global bee deaths. In: Roundtables of the Commission for Ecology 43: 87–94, here 88, 94.
  4. ↑ Moritz, RF 2014: The causes of global bee deaths. In: Roundtables of the Commission for Ecology 43: 87–94; Lu et al. 2014: Sub-lethal exposure to neonicotinoids impaired honey bees winterization before proceeding to colony collapse disorder. In: Bulletin of Insectology 67 (1): 125-130; Staveley, JP; Law, SA; Fairbrother, A. & Menzie, CA 2014: A Causal Analysis of Observed Declines in Managed Honey Bees (Apis mellifera). In: Human and Ecological Risk Assessment. To International Journal 20 (2): 566-591.
  5. ↑ The great insect mortality - Reasons for the Die Umweltinstitut München, accessed on May 22, 2019
  6. ^ Bienensterben Europäische Tier- und Naturschutz eV accessed on May 22, 2019
  7. ↑ Wild bees: "Bienensterben" on Wildbienen.de accessed on May 22, 2019
  8. ↑ Dennis vanEngelsdorp, Jay D. Evans, Claude Saegerman, Chris Mullin, Eric Haubruge, Bach Kim Nguyen, Maryann Frazier, Jim Frazier, Diana Cox-Foster, Yanping Chen, Robyn Underwood, David R. Tarpy, Jeffery S. Pettis: Colony Collapse Disorder: A Descriptive Study . In: PLoS ONE . tape 4 , no. 8 , 2009, p. e6481 , doi : 10.1371 / journal.pone.0006481 .
  9. ↑ FAOSTAT, 2016.
  10. ↑ Marcelo A. Aizen, Lawrence D. Harder: The Global Stock of Domesticated Honey Bees Is Growing Slower Than Agricultural Demand for Pollination . In: Current Biology . tape 19 , no. 11 , 2009, p. 915-918 , doi : 10.1016 / j.cub.2009.03.071 .
  11. ↑ a b c d Dennis vanEngelsdorp, Marina Doris Meixner: A historical review of managed honey bee populations in Europe and the United States and the factors that may affect them . In: Journal of Invertebrate Pathology . tape 103 , January 2010, p. S80-S95 , doi : 10.1016 / j.jip.2009.06.011 .
  12. ↑ Karafyllis, NC / Friedmann, G. 2017: No honey licking. Bees as 'ecosystem service providers' and natural surroundings. In: Natural Philosophy. A text and study book. Tübingen, UTB / Mohr Siebeck: 292–302, here 295.
  13. ↑ Honey Bee Health and Colony Collapse Disorder . ARS.
  14. ^ A b Hannah Nordhaus: An environmental journalist's lament . The Breakthrough, Summer 2011.
  15. ↑ Colony Loss 2015–2016: Preliminary Results . Bee Informed Partnership, May 4, 2016. Accessed March 8, 2017.
  16. ↑ Kathleen V. Lee, Nathalie Steinhauer, Karen Rennich, Michael E. Wilson, David R. Tarpy, Dewey M. Caron, Robyn Rose, Keith S. Delaplane, Kathy Baylis, Eugene J. Lengerich, Jeff Pettis, John A. Skinner , James T. Wilkes, Ramesh Sagili, Dennis vanEngelsdorp: A national survey of managed honey bee 2013–2014 annual colony losses in the USA . In: Apidology . tape 46 , no. 3 , 2015, p. 392-305 , doi : 10.1007 / s13592-015-0356-z .
  17. ↑ Nicola Seitz, Kirsten S. Traynor, Nathalie Steinhauer, Karen Rennich, Michael E. Wilson, James D. Ellis, Robyn Rose, David R. Tarpy, Ramesh R. Sagili, Dewey M. Caron, Keith S. Delaplane, Juliana Rangel , Kathleen Lee, Kathy Baylis, James T. Wilkes, John A. Skinner, Jeffery S. Pettis & Dennis vanEngelsdorp: A national survey of managed honey bee 2014–2015 annual colony losses in the USA . In: Journal of Apicultural Research . tape 54 , no. 4 , 2015, p. 292-304 , doi : 10.1080 / 00218839.2016.1153294 .
  18. ↑ a b Romée van der Zee, Lennard Pisa, Sreten Andonov, Robert Brodschneider, Jean-Daniel Charrière, Róbert Chlebo, Mary F Coffey, Karl Crailsheim, Bjørn Dahle, Anna Gajda, Alison Gray, Marica M Drazic, Mariano Higes, Lassi Kauko , Aykut Kence, Meral Kence, Nicola Kezic, Hrisula Kiprijanovska, Jasna Kralj, Preben Kristiansen, Raquel Martin Hernandezk, Franco Mutinelli, Bach Kim Nguyen, Christoph Otten, Asli Özkırım, Stephen F Pernal, Magnus Petersoni, Gavin Ramsaywa, Victoria, Violeta Santrac Soroker, Grażyna Topolska, Aleksandar Uzunov, Flemming Vejsnæs, Shi Wei, Selwyn Wilkins: Managed honey bee colony losses in Canada, China, Europe, Israel and Turkey, for the winters of 2008–9 and 2009–10 . In: Journal of Apicultural Research . tape 51 , no. 1 , 2012, p. 100-114 , doi : 10.3896 / IBRA.1.51.1.12 .
  19. ↑ Ernesto Guzmán-Novoa, Leslie Eccles, Yireli Calvete, Janine Mcgowan, Paul G. Kelly, Adriana Correa-Benítez: Varroa destructor is the main culprit for the death and reduced populations of overwintered honey bee (Apis mellifera) colonies in Ontario, Canada . In: Apidology . tape 41 , no. 4 , 2010, p. 443-450 , doi : 10.1051 / apido / 2009076 .
  20. ↑ Romée van der Zee, Robert Brodschneider, Valters Brusbardis, Jean-Daniel Charrière, Róbert Chlebo, Mary F Coffey, Bjørn Dahle, Marica M Drazic, Lassi Kauko, Justinas Kretavicius, Preben Kristiansen, Franco Mutinelli, Christoph Otten, Magnarus Peterson, Aiv Raudmets, Violeta Santrac, Ari Seppälä, Victoria Soroker, Grażyna Topolska, Flemming Vejsnæs, Alison Gray: Results of internationally standardized beekeeper surveys of colony losses for winter 2012–2013: analysis of winter loss rates and mixed effects modeling of risk factors for winter loss . In: Journal of Apicultural Research . tape 53 , no. 1 , 2014, p. 19-34 , doi : 10.3896 / IBRA.1.53.1.02 .
  21. ↑ Antoine Jacques, Marion Laurent, Magali Ribiere-Chabert, Mathilde Saussac, Stéphanie Bougeard, Pascal Hendrikx, Marie-Pierre Chauzat: Statistical analysis on the EPILOBEE dataset: explanatory variables related to honeybee colony mortality in EU during a 2 year survey . In: EFSA Supporting Publications . tape 13 , no. 4 , April 6, 2016, p. 1–228 , doi : 10.2903 / sp.efsa.2016.EN-883 .
  22. ↑ Antoine Jacques, Marion Laurent, EPILOBEE Consortium, Magali Ribière-Chabert, Mathilde Saussac, Stéphanie Bougeard, Giles E. Budge, Pascal Hendrikx, Marie-Pierre Chauzat: A pan-European epidemiological study reveals honey bee colony survival depends on beekeeper education and disease control . In: PLoS ONE . tape 12 , no. 3 , March 9, 2017, p. 17 , doi : 10.1371 / journal.pone.0172591 .
  23. ↑ Elke Genersch, Werner von der Ohe, Hannes Kaatz, Annette Schroeder, Christoph Otten, Ralph Büchler, Stefan Berg, Wolfgang Ritter, Werner Mühlen, Sebastian Gisder, Marina Meixner, Gerhard Liebig, Peter Rosenkranz: The German bee monitoring project: a long term study to understand periodically high winter losses of honey bee colonies . In: Apidology . tape 41 , no. 3 , 2010, p. 332-352 , doi : 10.1051 / apido / 2010014 .
  24. ↑ [ https://www.uni-hohenheim.de/fileadmin/einrichtungen/bienenmonitoring/Dokumente/ADIZ_db_IF_10_2011_S09.pdf The German bee monitoring system for pesticide residues in bee bread]. ADIZ / db / IF 10/2011.
  25. ↑ University of Hohenheim: Final Report DEBIMO, funding 2011-2013 , April 14, 2014.
  26. ↑ Pesticides are not a cause of death for bees? NABU, January 25, 2011.
  27. ↑ Opinion on DEBIMO criticism . University of Hohenhein, January 29, 2011.
  28. ↑ Chao Chen, Qingsheng Niu, Wenzhong Qi, Chunying Yuan, Songkun Su, Shidong Liu, Yingsheng Zhang, Xuewen Zhang, Ting Ji, Rongguo Dai, Zhongyin Zhang, Shunhai Wang, Fuchao Gao, Haikun Guo, Liping Lv, Guiling Ding & Wei Shi: Survey results of honey bee (Apis mellifera) colony losses in China (2010–2013) . In: Journal of Apicultural Research . tape 55 , no. 1 , 2016, p. 29-37 , doi : 10.1080 / 00218839.2016.1193375 .
  29. ↑ Christian WW Pirk, Hannelie Human, Robin M Crewe, Dennis vanEngelsdorp: A survey of managed honey bee colony losses in the Republic of South Africa – 2009 to 2011 . In: Journal of Apicultural Research . tape 53 , no. 1 , 2014, p. 35-42 , doi : 10.3896 / IBRA.1.53.1.03 .
  30. ↑ a b Elke Genersch, Werner von der Ohe, Hannes Kaatz, Annette Schroeder, Christoph Otten, Ralph Büchler, Stefan Berg, Wolfgang Ritter, Werner mills, Sebastian Gisder, Marina Meixner, Gerhard Liebig, Peter Rosenkranz: The German bee monitoring: A longitudinal study to understand periodically occurring, high winter losses in honey bee colonies . In: Apidology . tape 41 , no. 3 , 2010, p. 332-352 , doi : 10.1051 / apido / 2010014 .
  31. ↑ a b Bettina Jakob: A professor is fighting against bee deaths. Interview with Prof. Peter Neumann. (No longer available online.) University of Bern , January 8, 2013, archived from the original on April 22, 2016 ; Retrieved April 30, 2013 .
  32. ↑ USDA, 2013: Report on the National Stakeholders Conference on Honey Bee Health. National Honey Bee Health Stakeholder Conference Steering Committee ( Memento of the original from May 20, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.usda.gov
  33. ↑ EASAC (ed.): Ecosystem services, agriculture and neonicotinoids . EASAC policy report 26. 2015, ISBN 978-3-8047-3437-1 ( PDF ).
  34. ↑ Lars Straub, Geoffrey R. Williams, Beatriz Vidondo, Kitiphong Khongphinitbunjong, Gina Retschnig, Annette Schneeberger, Panuwan Chantawannakul, Vincent Dietemann, Peter Neumann: Neonicotinoids and ectoparasitic mites synergistically impact honeybees. In: Scientific Reports. 9, 2019, doi: 10.1038 / s41598-019-44207-1 .
  35. ↑ a b Main cause of the great bee deaths found in: Welt Online from March 24, 2011.
  36. ↑ A people of bees, quo vadis? in: faz.net from April 6, 2011.
  37. ↑ NABU and BUND criticize bee monitoring. BUND press release from January 25, 2011.
  38. ↑ Francis LW Ratnieks, Norman L. Carreck: Clarity on Honey Bee Collapse? In: Science . tape 327 , no. 5962 , January 8, 2010, p. 152-153 , doi : 10.1126 / science.1185563 .
  39. ↑ Researchers find reason for bee deaths. In: Spiegel Online. August 25, 2009. Retrieved July 21, 2010 .
  40. ↑ Reed M. Johnson et al. a .: Changes in transcript abundance relating to colony collapse disorder in honey bees ( Apis mellifera ) . In: Proceedings of the National Academy of Sciences . 2009, doi : 10.1073 / pnas.0906970106 ( pnas.org [PDF; 796 kB ]).
  41. ↑ A. Core, C. Runckel, J. Ivers, C. Quock, T. Siapno, et al. (2012): A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis. PLoS ONE 7 (1): e29639. doi: 10.1371 / journal.pone.0029639 .
  42. ↑ Antje Findeklee: Parasitology: New trace in bee deaths . Report at Spektrum.de from January 3, 2012.
  43. ↑ Lewis H. Ziska: Rising atmospheric CO2 is reducing the protein concentration of a floral pollen source essential for North American bees . In: Proceedings of the Royal Society B . tape 283 , no. 1828 , 2016, doi : 10.1098 / rspb.2016.0414 .
  44. ^ Rolf Forster, Erdmann Bode, Dietrich Brasse: The "Bienensterben" in the winter of 2002/2003 in Germany. On the state of scientific knowledge . Federal Office for Consumer Protection and Food Safety, Braunschweig 2005, ISBN 3-9810189-2-3 ( bund.de [PDF] conference report).
  45. ^ Reed M. Johnson, Marion D. Ellis, Christopher A. Mullin, Maryann Frazier: Pesticides and honey bee toxicity - USA. In: Apidology . 41 (3), 2010, pp. 312-331, (section Conclusions) doi: 10.1051 / apido / 2010018 .
  46. ^ Francisco Sánchez-Bayo, Kris AG Wyckhuys: Worldwide decline of the entomofauna: A review of its drivers. In: Biological Conservation. 232, 2019, p. 8, doi: 10.1016 / j.biocon.2019.01.020 .
  47. ↑ According to studies by the Julius Kühn Institute, seeds dressed with clothianidin are the cause of current damage to bees in Baden-Württemberg. In: Information Service Science. May 16, 2008, accessed July 21, 2010 .
  48. ↑ Federal Office for Consumer Protection and Food Safety (Ed.): Reports on Plant Protection Products 2008. Status report on bee poisoning by insecticidal seed treatment agents in southern Germany in 2008 . Birkhäuser, Basel 2009, ISBN 978-3-0346-0052-1 , p. 5 ( bund.de [PDF]).
  49. ↑ BVL re-enacts approvals for plant protection products for the treatment of rapeseed. (No longer available online.) In: Federal Office for Consumer Protection and Food Safety. June 25, 2008, archived from the original on January 4, 2016 ; Retrieved July 21, 2010 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.bvl.bund.de
  50. ↑ Mickaël Henry, Maxime Beguin, Fabrice Requier, Orianne Rollin, Jean-François Odoux, Pierrick Aupinel, Jean Aptel, Sylvie Tchamitchian, Axel Decourtye: A Common Pesticide Decreases Foraging Success and Survival in Honey Bees. Science , March 29, 2012. doi: 10.1126 / science.1215039
  51. ↑ Philipp Mimkes: Bee deaths now also in Germany . In: Keyword BAYER . No. 2 , 2003 ( cbgnetwork.org ).
  52. ↑ Sven Preger: Silent humming. (No longer available online.) In: Süddeutsche Zeitung . November 26, 2003, archived from the original on March 20, 2007 ; Retrieved March 13, 2007 .
  53. ↑ Wolfgang Weitlaner: Beekeeping Associations: Pesticide to blame for bee deaths. In: innovations report. September 10, 2004, accessed on July 21, 2010 (forum for science, industry and business financed by large German companies).
  54. ↑ Use of Common Pesticide, Imidacloprid, Linked to Bee Colony Collapse. News from ScienceDaily from April 5, 2012.
  55. ↑ Bee deaths : Austria voted against the ban on pesticides at tt.com, April 29, 2013 (accessed on March 3, 2020).
  56. ↑ EU member states agree on pesticide ban: More protection for Europe's bees at tagesschau.de, April 29, 2013 (accessed April 30, 2013).
  57. ^ Peter Neumann: Ecosystem services: Academies review insecticide harm . In: Nature . tape 520 , 2015, p. 157 , doi : 10.1038 / 520157a .
  58. ^ Ecosystem services, agriculture and neonicotinoids . April 8, 2015.
  59. ↑ Evaluation of the data on clothianidin, imidacloprid and thiamethoxam for the updated risk assessment to bees for seed treatments and granules in the EU | European Food Safety Authority. Accessed March 19, 2018 (English).
  60. ↑ Fight against bee mortality: EU bans neonicotinoids in fields ( memento of July 24, 2018 in the Internet Archive ); br.de , April 27, 2018.
  61. Jump up ↑ bee deaths: Investigations against farmers in Udine ; In: derstandard.at, May 5, 2018, accessed on May 6, 2018.
  62. ↑ Erick VS Motta, Kasie Raymann, Nancy A. Moran: Glyphosate perturbs the gut microbiota of honey bees. In: Proceedings of the National Academy of Sciences. , P. 201803880, doi: 10.1073 / pnas.1803880115 .
  63. ↑ Illegal material: bee deaths in Aargau. In: schweizerbauer.ch . October 20, 2019, accessed October 20, 2019 .
  64. ↑ Lars Straub, Verena Strobl, Peter Neumann: The need for an evolutionary approach to ecotoxicology. In: Nature Ecology & Evolution. April 23, 2020, doi: 10.1038 / s41559-020-1194-6 .
  65. ↑ Risk assessments of chemicals for the environment are insufficient. In: unibe.ch . April 23, 2020, accessed April 27, 2020 .
  66. ↑ Colony Collapse Disorder . In: Fruit Times . tape 26 , no. 1 , January 23, 2007 ( online ( memento of June 25, 2010 in the Internet Archive ) [accessed on July 21, 2010]).
  67. ↑ Bee Mites Suppress Bee Immunity, Open Door For Viruses And Bacteria. In: ScienceDaily. May 18, 2005, accessed July 21, 2010 .
  68. ↑ Michael C. Otterstatter, James D. Thomson: Does Pathogen Spillover from Commercially Reared Bumble Bees Threaten Wild Pollinators? In: PLoS one . 3 number = 7, 2008, p. e2771 , doi : 10.1371 / journal.pone.0002771 .
  69. ↑ Jan Osterkamp: Zuchthummel with collateral damage. In: spectrum direct. July 23, 2008.
  70. ↑ For details and sources see the article Nosemose .
  71. ^ A b c d Peggy G. Lemaux: Genetically Engineered Plants and Foods: A Scientist's Analysis of the Issues (Part II). Annual Review of Plant Biology , Volume 60, pp. 511-559. doi: 10.1146 / annurev.arplant.043008.092013 .
  72. ↑ Project leader: Prof. Dr. Hans-Hinrich Kaatz sub-project: Effects of Bt maize pollen on honeybees - method development for effectiveness testing and monitoring. Funding number: 031631J Final report 2004
  73. ^ Effects of Bt maize pollen on honeybees. (No longer available online.) In: biosicherheit.de. October 12, 2005, archived from the original on December 22, 2015 ; accessed on September 7, 2016 .
  74. ↑ a b H. Stever u. a .: Change in behavior under electromagnetic exposure. Pilot study 2005 ( Memento from July 24, 2011 in the Internet Archive )
  75. ↑ a b H. Stever u. a .: Changes in behavior of the honey bee Apis mellifera under electromagnetic exposure. Follow-up experiment 2006. (PDF; 359 kB) (No longer available online.) Educational informatics working group at the University of Koblenz-Landau, 2006, archived from the original on July 24, 2011 ; Retrieved July 21, 2010 .
  76. ^ A b Daniel Favre: Mobile phone-induced honeybee worker piping . In: Apidology . tape 42 , no. 3 , May 2011, p. 270-279 , doi : 10.1007 / s13592-011-0016-x .
  77. ↑ Marcelo A. Aizen, Lucas A. Garibaldi, Saul A. Cunningham, Alexandra M. Klein: How much does agriculture depend on pollinators? Lessons from long-term trends in crop production . In: Annals of Botany . tape 103 , 2009, p. 1579-1588 , doi : 10.1093 / aob / mcp076 .
  78. ↑ Hans Schuh: The bee, money and death . Zeit Online, May 24, 2007