Characteristics of Colony Collapse Disorder - Case Study Example

?COLONY COLLAPSE DISORDER Characteristics of Colony Collapse Disorder Colony collapse disorder (CCD) is an idiopathic phenomenon in which there is a sudden loss of honey bee (Apis mellifera L.) colonies in the United States. Beekeepers initially notice it as an unexpected emptying of the hives, the absence of adult bees, with the young broods intact (Watanabe, 2008). Such occurrences in the beekeeping industry were recorded since 1869 (vanEngelsdorp et al., 2009). However, it was only in 2006 that Colony collapse disorder was coined and characterized. The study of CCD is a challenging one. First, researchers have to account the seasonal variability of both the physiology of bees and the environmental factors (Watanabe, 2008). Despite that, many studies on CCD have already been conducted, and are now ongoing. One of the most important things to be done is to define CCD. Thus, further investigation saw that loss of adult worker bees drives the process. Looking closely into CCD-affected colonies, there were no increased number of dead worker bees found within and surrounding the hives. In addition, the protection of the hives is intact, as invasion of hive pests and kleptoparasitism were found to be delayed (vanEngelsdorp et al., 2009). Implications of CCD CCD is a serious issue because of the many industries that depend on it. Aside from their produce, the bees are used to pollinate plants such as almonds and blueberries, thus playing a major role in agriculture. In fact, the industry of beekeeping is so important that laws that protect it are being legislated. One good example is the Honeybee Act of 1922, which disallows the importation of bees from other countries such as Europe and Australia to prevent the spread of tracheal mites and other pathogens from other countries to the unprotected bees in the United States (Watanabe, 2008). CAUSES OF CCD In the epizootiological study of vanEngelsdorp et al.(2009) that looked into 61 possible causes of CCD, no single risk factor increased the susceptibility of apiaries to CCD. To do this, morphological measurements and genetic lineage were taken on both brood and adult bees. Samples from the bees, waxcomb and pollens were also analyzed for known honeybee parasites (varroa mites, Varroa destructor, and honeybee tracheal mites, Acarapis woodi), pathogens (bee viruses and Nosema spp.), pesticide residues, and protein levels. Through genetic analysis, the bees tested were found to be mostly Eastern European in origin. As expected more weak and dead bees were seen in CCD apiaries as compared to healthy ones. In addition, CCD colonies tend to be clustered together rather than being distributed randomly in the apiary. This, according to the authors of the study, points to a possible infective agent or a common risk factor these CCD colonies were exposed to. Investigating further, no difference was found between the CCD-affected and healthy bees in terms on their body protein levels and morphometric measurements. This means that nutrition is not the primary root of CCD. However, viruses and Nosema loads and decreased levels of synthetic acaricide coumaphos, fluvalinate and Esfenvalerate were found among CCD-affected apiaries than the normal colonies. It is interesting to note that, contrary to infection as the seemingly primary cause of CCD, tracheal mites were found to be three times more prevalent in control apiaries than in CCD-affected ones. Injuring pathogens and pesticides How can these findings explain the sudden loss of adult bees without evidences of a great number of dead bees within and surrounding the hives? Worker bee longevity was found to be significantly reduced when they are exposed to pathogens as well as sublethal levels of coumaphos during their larval and pupal stages. Quite possibly, CCD bees lack detoxification enzymes needed for the cross-resistance to coumaphos and other pesticides, causing bad effects on their health. Diseased states thus play a major role in colony collapse. Although some may argue that control colonies were exposed as well, with tracheal mites having been found in a greater extent in them, this finding was only due to the fact that these pests are found among adult bees, which are sorely lacking in CCD apiaries. Watanabe (2008) reported that Israeli acute paralysis virus (IAPV) is found among CCD-affected bees, although whether or not it causes the phenomenon still remains a mystery. Described first in Israel in 2004, the virus has somehow made its way to the United States, with the probable route still very much questionable. Researchers are looking into the role of small hive beetle Aethina tumida and Manchurian royal jelly in the importation of IAPV into the country. The role of IAPV in CCD, according to Watanabe (2008), is very much probable because it has already been proven through a study that the virus can kill insects, such as cockroaches. However, debate over the role of IAPV in CCD development still ensues as IAPV viruses have also been found in healthy bee colonies. Emigration of diseased adult bees and prematurity of replacement bees In addition, vanEngelsdorp et al. (2009) explained that infected adult bees emigrate from the hive in efforts to protect the rest of the bees from further damage. In effect, disease, pesticide exposure and emigration of adult bees lead to the decreased number of older bees in the colony, forcing the premature conversion of young bees into foraging bees to sustain the productivity of the hive. However, their prematurity makes them more susceptible to pathogens and other injuring factors, further depleting the bee population. When the mortality rates goes beyond the rate at which bees are replaced, depopulation ensues, and the colony eventually dies. CHANGING PARADIGMS With the evidences presented, it is quite clear that no single factor can induce as monumental as CCD. Thus, efforts on finding such single factor, just like what the group of vanEngelsdorp (2009) was trying to do, are futile and unnecessary. CCD is caused by an interplay of injuring agents. What science should concentrate now is to identify the risks for developing CCD. The role of genetics and lineage is a good start in this risk assessment. This is important as it is very probable that a certain breed of bees is more susceptible to CCD that other honeybee breeds. Upon identification of risk factors and their relative bearing compared to one another, what should be done is to find ways to prevent CCD from occurring. A plan on this endeavour can involve controlling the risks for CCD by practical changes in CCP. These plans may involve breeding modifications, more judicious and informed use of pesticides. References vanEngelsdorp D, Evans JD, Saegerman C, Mullin C, Haubruge E, et al. (2009) Colony Collapse Disorder: A Descriptive Study. PLoS ONE 4(8): e6481 Watanabe, MF. (2008). Colony Collapse Disorder: Many Suspects, No Smoking Gun. BioScience. 58(5): 384-388. Read More