Colony Collapse Disorder in Honey Bees - Research Paper Example

 Abstract The Honey bee population is currently facing a serious threat as several adult bee populations are failing to return to their hives. Scientists have named this phenomenon as the Colony Collapse Disorder due to the severity and unusual characteristics of the condition. As honey bees are considered to be the principle pollinators for many crops the onset of this disorder has resulted in the loss of several billions of dollars in revenue. The enormity of the situation has compelled scientist to unravel the cause behind the occurrence of such as disorder. Several causative factors such as pathogens, pesticides, antibiotics and other factors such as climatic changes have identified as possible reasons for the disorder. Based on the findings adequate provisions for research, monitoring, support for beekeepers, and stricter regulations for use of agricultural chemicals should be implemented to control the colony collapse disorder. Introduction Honey bees play a vital role in the pollination of crops as one-third of fruits and vegetables are produced by honey bee pollination. The revenue gained from the use of honey bees as commercial pollinators is estimated to be around $20 billion annually. Beginning from 2006, various beekeepers in most states in the US have reported a considerable decline in the population of honey bees. Considering the severity of the condition this phenomenon is widely being referred to as the colony collapse disorder (CDD), by scientists (Johnson, 2010). The honey bees that leave for the forage largely do not return back to their hives and this is especially witnessed to a large extent with migratory bees which are trucked from one country to another for pollination purposes. Scientists have begun to unravel the causes behind this phenomenon as it is a major source of income for the beekeepers and also the farmers depend on it for crop production (Colony Collapse Disorder; Johnson, 2010). In the earlier times a 10 percent loss in honey bee population in a season was considered to be normal, which then rose to 30 percent due to infection by parasitic mites and beginning from 2006 many commercial beekeepers have reported a loss of 30 to 90 percent average colony loss with the onset of CDD. Even the surviving colonies showed weak viability. Though a majority of the losses have been attributed to known causes about 25% of the loss is estimated to have occurred due to CCD. These losses of colonies occur throughout the year and are not seasonal. The major symptoms of this condition are the rapid loss of adult bee workers without any accumulation of dead bees in the hive which is an indication that these bees are not retuning back to the hive that is highly unusual in case of the bee population. These adult bees leave behind their brood which is generally inactive. The queen bee is generally present and actively laying eggs (Johnson, 2010). Research carried out to determine the causative factors for this condition has found out that CCD could be a syndrome which is not caused by any one particular factor but a combination of several factors. Some of the major possible factors that threaten the bee population are viruses, parasites and microbes, pesticides, antibiotics, miticides, radiations, genetically modified crops and climatic changes (Colony Collapse Disorder; Johnson, 2010). The USDA’s Agriculture Research Service, the Pennsylvania State University and several other universities are conducting most of the current research to unravel the cause of this phenomenon (Johnson, 2010). A recent study carried out by the Washington State University has shown that CCD could be caused due to a combination of toxic chemicals and pathogens present in honeycombs as the bees present in such combs had reduced longevity (Gutierrez, 2010). Of these, chronic exposures to pesticides, miticides and antibiotics have been shown to have an impact on the immune system of the honey bees and hence on their response to infection. These toxic chemicals are believed to cause the colony to collapse either by themselves or by combining with each other, which would result in increased toxicity to the hive. In addition scientists are also studying the combinatory effects of viruses that infect the hive and these chemicals and such studies have found that these chemicals could combine with viruses and thereby reduce the immunity of the bees and increase their susceptibility to infection (Honeybees’ Colony Collapse Disorder). Antibiotics are primarily used to control the growth of bacteria in beehives by either killing or inhibiting the growth of bacteria. Miticides are also pesticides which are used to control the mite population and different varieties of miticides like antibiotic miticides and carbamate miticides are available for use. Both antibiotics and miticides are widely being used by beekeepers. The pesticide class includes the commonly used insecticides and, more particularly, in this case the nicotine-based pesticides (Colony Collapse Disorder; Assessment of Current Miticide). Pesticides applied to crops to protect them from insects and other pests are posing a great threat to the honey bees that play a vital role in crop pollination. A recent class of insecticides, which is being widely used in farming practices, is the nicotine-based insecticides or neonicotinoids. These systemic insecticides are directly applied to the soil and are later taken up by the plant tissues and their residues are found in the pollen and nectar. These insecticides by themselves tend to remain in the soil and are retained there for long periods due to their increased persistence (Colony Collapse Disorder). Various studies conducted have indicated the presence of insecticides and other pesticides in the pollens. Nicotine-based insecticides, like imidacloprid which is the most widely used in this class, affect the central nervous system of the insects by speeding up nerve impulses and block vital neuronal pathways and they affect the honey bees in a similar manner. Studies have established that pollens contain a significant quantity of the insecticide upon absorption form the soil and this polluted pollen has been widely touted to be a major cause of honey bee colony death. Though they are not present at lethal doses, prolonged exposure to these chemicals could result in conditions like CCD. In addition, studies have also shown that these chemicals at the sub lethal levels can cause problems in honey production and foraging of the bees as flight activity and olfactory discrimination was affected and the physiological effects manifested when the dosage level was gradually increased (Colony Collapse Disorder; Johnson, 2010). Thus the possible effects of these chemicals have been well established. But given the exposure dosage it is quite difficult to ascertain for sure that these are the major causative factors for CCD and no detailed study has been conducted on residual pesticide content and their degree of toxicity in CCD affected colonies per se. Hence a more detailed and thorough investigation is warranted to study the extent to which these can cause the disorder. Miticides are a class of pesticides, which are being widely used to improve the quality of the beehive and the health and longevity of the worker bee. They are however used in sub lethal doses and the effect of two most commonly used miticides, Apistan and CheckMite+, on the bee population is being studied. The survivability, honey production and foraging rates are being assessed in accordance with the CCD action plan prepared by the national CCD steering committee to test the effects of miticides and their possible role in causing the disorder (Assessment of Current Miticide). One severe disadvantage associated with miticides is that mites gradually develop resistance to them over time and hence newer forms of the chemical are constantly under development. These new chemicals can harm the hive and in addition, miticides can also accumulate in the honey combs and when present at a higher level they can possibly endanger the survival of the bees (Bee Colony Collapse). In addition to chemicals, infection of the hive by parasitic mites such as Varroa destructor and viruses such as the Israel acute paralysis virus (IAPV), which can be transmitted to the hive by the Varroa mite are also being considered to be key organisms that might cause the disorder. In the study conducted by the Washington State University has revealed that high concentrations of the pesticides, fluvalinate and coumaphos, which are used to eradicate the varroa mites might also contribute to CCD (Gutierrez, 2010). Studies have also related infection by the fungus Nosema ceranae with CCD, but a direct link is yet to be established. This pathogen affects the food processing ability of the bees thus making them susceptible to pathogens and chemicals (Honeybees’ Colony Collapse Disorder; Gutierrez, 2010; Johnson, 2010). Genetically modifies crops have also been scrutinized as a possible cause for this disorder as they release insecticidal toxins from the bacterium Bacillus thuringiencis. Research has revealed that these toxins have a negative effect on the navigation of the bees and CCD has been found to occur in places where Bt crops are grown. Beekeeping practices and changes in the hive due to migration from one place to another is also being studied and so are the effects due to climatic changes and electromagnetic radiations from mobiles, cell towers and wireless networks (Honeybees’ Colony Collapse Disorder). In conclusion, while research about the actual cause for the onset of CCD is still in the primitive stages, zeroing on the exact cause should not take long as all the possible causative factors are being analyzed currently. The colony collapse disorder is truly a menacing problem and suitable steps such as research and monitoring, technical assistance to beekeepers, stricter regulations for use of agricultural pesticides and insecticides will have to be implemented before agricultural practices are adversely affected. Reference: 1. Colony Collapse Disorder in Honey Bees. Retrieved December 6, 2010, from < http://kanat.jsc.vsc.edu/student/lees/maincontent.htm > 2. Assessment of Current Miticide Use on Honey Bee Longevity and Colony Health. United States Department of Agriculture. Retrieved December 6, 2010, from < http://www.reeis.usda.gov/web/crisprojectpages/213332.html> 3. Honeybees’ Colony Collapse Disorder: Where have all the workers gone? Retrieved December 6, 2010, from 4. Bee Colony Collapse Disorder: Could It Be Parasites, Pathogens Or Pesticides? ScienceDaily. Retrieved December 6, 2010, from < http://www.sciencedaily.com/releases/2007/05/070511210207.htm> 5. Johnson, R. (2010). Honey Bee Colony Collapse Disorder. CRS report for Congress. Retrieved 6, December, 2010, from http://www.fas.org/sgp/crs/misc/RL33938.pdf 6. Gutierrez, D. (2010). Honey Bee Colony Collapse Disorder Finally Explained: Too Many Chemicals. Natural News. Retrieved 6, December, 2010, from http://www.naturalnews.com/028429_colony_collapse_disorder_chemicals.html Read More