Bees and bee pests

Some wiki research on bees of various kinds, and bee pests.
In case you were wondering…

http://en.wikipedia.org/wiki/Western_honey_bee

The European honey bee or Western honey bee (Apis mellifera) is a species of honey bee. The genus Apis is Latin for “bee”, and mellifera comes from the Latin meli- “honey” and ferre “to bear” — hence the scientific name means “honey-bearing bee”. The name was coined in 1758 by Carolus Linnaeus who, realizing that the bees do not bear honey, but nectar, tried later to correct it to Apis mellifica (“honey-making bee”) in a subsequent publication. However, according to the rules of synonymy in zoological nomenclature, the older name has precedence. Some people who are unaware of this still use the incorrect subsequent spelling. As of October 28, 2006, the Honey Bee Genome Sequencing Consortium fully sequenced and analyzed the genome of Apis mellifera.

African bees… there’s several species, and thi is one of the better ones, but alas, not what we ended up with.

Apis mellifera sahariensis, classified by Baldensperger, 1932 – from the Moroccan desert oases of Northwest Africa. This sub-species faces few predators other than humans and is therefore very gentle. Moreover, because of the low density of nectar-producing vegetation around the oases it colonizes, it forages up to five miles, much farther than sub-species from less arid regions. Other authorities say that while colonies of this species are not much inclined to sting when their hives are opened for inspection, they are, nevertheless, highly nervous….

Genome

The European honey bee is the third insect, after the fruit fly and the mosquito, to have its genome mapped. According to the scientists who analysed its genetic code, the honey bee originated in Africa and spread to Europe in two ancient migrations.[3] They have also discovered that the number of genes in the honey bees related to smell outnumber those for taste, and they have fewer genes for immunity than the fruit fly and the mosquito. [4] The genome sequence revealed several groups of genes, particularly the genes related to circadian rhythms, were closer to vertebrates than other insects. Genes related to enzymes that control other genes were also vertabratelike.[5]

European honey bee populations have recently faced threats to their survival. North American and European populations were severely depleted by varroa mite infestations in the early 1990s, and US beekeepers were further affected by Colony Collapse Disorder in 2006 and 2007.[7] Chemical treatments against Varroa mites saved most commercial operations and improved cultural practices. New bee breeds are starting to reduce the dependency on miticides (acaracides) by beekeepers. Feral bee populations were greatly reduced during this period but now are slowly recovering, mostly in areas of mild climate, owing to natural selection for Varroa resistance and repopulation by resistant breeds. Further, Insecticides, particularly when used in violation of label directions, have also depleted bee populations[citation needed], while various bee pests and diseases are becoming resistant to medications (e.g. American Foul Brood, Tracheal Mites and Varroa Mites).

[edit] Environmental hazards

In North America, Africanized bees have spread across the southern United States where they pose a small danger to humans, although they may make beekeeping (particularly hobby beekeeping) difficult and potentially dangerous.

Colony Collapse disorder

http://en.wikipedia.org/wiki/Colony_Collapse_Disorder

Colony Collapse Disorder

(or

CCD

) is a phenomenon in which worker bees from a

beehive

or

Western honey bee

colony abruptly disappear. While such disappearances have occurred throughout the history of

apiculture

, the term

Colony Collapse Disorder

was first applied to a drastic rise in the number of disappearances of Western honey bee colonies in

North America

in late 2006.

[1]

Honey bees entering a beehive.

Honey bees entering a beehive.

European beekeepers observed similar phenomena in Belgium, France, the Netherlands, Greece, Italy, Portugal, and Spain,[2] and initial reports have also come in from Switzerland and Germany, albeit to a lesser degree.[3] Possible cases of CCD have also been reported in Taiwan since April 2007.[4]

The cause or causes of the syndrome are not yet fully understood, although many authorities attribute the problem to biotic factors such as: Varroa mites and insect diseases (i.e., pathogens[5] including Nosema apis and Israel acute paralysis virus[6][7]). Other proposed causes include environmental change-related stresses,[8] malnutrition and pesticides (e.g. neonicotinoids such as imidacloprid), and migratory beekeeping. More highly speculative possibilities have included both cell phone radiation and genetically modified (GM) crops with pest control characteristics,[9][10], though experts point out no evidence exists for either assertion.

Background

From 1971 to 2006, there was a dramatic reduction in the number of feral (gone wild) honeybees in the US (now almost absent);[11] and a significant, though somewhat gradual decline in the number of colonies maintained by beekeepers. This decline includes the cumulative losses from all factors such as urbanization, pesticide use, tracheal and Varroa mites, and commercial beekeepers retiring and going out of business. However, late in the year 2006 and in early 2007 the rate of attrition was alleged to have reached new proportions, and the term “Colony Collapse Disorder” was proposed to describe this sudden rash of disappearances.[1]

Limited occurrences resembling CCD have been documented as early as 1896,[5][12] and this set of symptoms has in the past several decades been given many different names (disappearing disease, spring dwindle, May disease, autumn collapse, and fall dwindle disease).[13] Most recently, a similar phenomenon in the winter of 2004/2005 occurred, and was attributed to Varroa mites (the “Vampire Mite” scare), though this was never ultimately confirmed. Nobody has been able to determine the cause of any past appearances of this syndrome. Upon recognition that the syndrome does not seem to be seasonally-restricted, and that it may not be a “disease” in the standard sense — that there may not be a specific causative agent — the syndrome was renamed.[14]

[edit] Symptoms

A colony which has collapsed from CCD is generally characterized by all of these conditions occurring simultaneously[15]:

  • Complete absence of adult bees in colonies, with little or no build-up of dead bees in or around the colonies.
  • Presence of capped brood in colonies. Bees normally will not abandon a hive until the capped brood have all hatched.
  • Presence of food stores, both honey and bee pollen:
Precursor symptoms that may arise before the final colony collapse are:

  • Insufficient workforce to maintain the brood that is present
  • Workforce seems to be made up of young adult bees
  • The Queen is present
  • The colony members are reluctant to consume provided feed, such as sugar syrup and protein supplement.

In the U.S., at least 24 different states

[8][16]

as well as portions of

Canada[17]

have reported at least one case of CCD. However, in many cases, beekeepers reporting significant losses of bees did not experience CCD, and a major part of the subsequent analysis of the phenomenon hinges upon distinguishing between true CCD losses and non-CCD losses.

[18]

In a survey of 384 responding beekeepers from 13 states, reporting the number of hives containing few or no bees in spring, only 23.8% met the specified criteria for CCD (that 50% or more of their dead colonies were found without bees and/or with very few dead bees in the hive or apiary).

[18]

In the US, despite highly variable anecdotal claims appearing in the media, the best documentation indicates that CCD-suffering operations had a total loss of 45% compared to the total loss of 25% of all colonies experienced by non-CCD suffering beekeepers in 2006-2007; it is further noted that non-CCD winter losses as high as 50% have occurred in some years and regions (e.g., 2000-2001 in

Pennsylvania

), though “normal” winter losses are typically considered to be in the range of 15-25%.

[18] Possible causes and research

The exact mechanisms of CCD are still unknown. One report indicates a strong but possibly non-causal association between the syndrome and the presence of the Israel acute paralysis virus.[7] Other factors may also be involved, however, and several have been proposed as causative agents; malnutrition, pesticides, pathogens, immunodeficiencies, mites, fungus, genetically modified (GM) crops, beekeeping practices (such as the use of antibiotics, or long-distance transportation of beehives) and electromagnetic radiation. Whether any single factor is responsible, or a combination of factors (acting independently in different areas affected by CCD, or acting in tandem), is still unknown. It is likewise still uncertain whether CCD is a genuinely new phenomenon, as opposed to a known phenomenon that previously only had a minor impact.

At present, the primary source of information, and presumed “lead” group investigating the phenomenon, is the Colony Collapse Disorder Working Group, based primarily at Penn State University. Their preliminary report pointed out some patterns, but drew no strong conclusions.[14] A survey of beekeepers early in 2007 indicates that most hobbyist beekeepers believed that starvation was the leading cause of death in their colonies, while commercial beekeepers overwhelmingly believed that invertebrate pests (Varroa mites, honey bee tracheal mites, and/or small hive beetles) were the leading cause of colony mortality.[18] A scholarly review in June 2007, similarly addressed numerous theories and possible contributing factors, but left the issue unresolved.[13]

In July 2007, the USDA released its “CCD Action Plan”, which outlines a strategy for addressing CCD consisting of four main components:[23]

  1. survey and data collection;
  2. analysis of samples;
  3. hypothesis-driven research; and,
  4. mitigation and preventative action.

As of late 2007, there is still no consensus of opinion, and no definitive causes have emerged; the schedule of presentations for a planned national symposium on CCD, titled “Colony Collapse Disorder in Honey Bees: Insight Into Status, Potential Causes, and Preventive Measures,” which is scheduled for December 11, 2007, at the meeting of the Entomological Society of America in San Diego, California, gives no indication of any major breakthroughs.[3]

[edit] Poor nutrition or malnutrition

One of the patterns reported by the group at Penn State was that all producers in a preliminary survey noted a period of “extraordinary stress” affecting the colonies in question prior to their die-off, most commonly involving poor nutrition and/or drought.[14] This is the only factor that all of the cases of CCD had in common in this report; accordingly, there is at least some significant possibility that the phenomenon is correlated to nutritional stress, and may not manifest in healthy, well-nourished colonies. This is similar to the findings of a later independent survey, in which small-scale beekeeping operations (up to 500 colonies) in several states reported their belief that malnutrition and/or weak colonies was the factor responsible for their bees dying, in over 50% of the cases, whether the losses were believed to be due to CCD or not.[18]

Some researchers have attributed the syndrome to the practice of feeding high fructose corn syrup (HFCS) to supplement winter stores. The variability of HFCS may be relevant to the apparent inconsistencies of results. European commentators have suggested a possible connection with HFCS produced from genetically modified corn.[3] If this were the sole factor involved, however, this should also lead to the exclusive appearance of CCD in wintering colonies being fed HFCS, but many reports of CCD occur in other contexts, with beekeepers who do not use HFCS.

General

Some researchers have commented that the pathway of propagation functions in the manner of a contagious disease; however, there is some sentiment that the disorder may involve an immunosuppressive mechanism,[24] potentially linked to the aforementioned “stress” leading to a weakened immune system. Specifically, according to researchers at Penn State: “The magnitude of detected infectious agents in the adult bees suggests some type of immunosuppression.” These researchers initially suggested a connection between Varroa destructor mite infestation and CCD, suggesting that a combination of these bee mites, deformed wing virus (which the mites transmit) and bacteria work together to suppress immunity and may be one cause of CCD.[25] This research group is reported to be focusing on a search for possible viral, bacterial, or fungal pathogens which may be involved.[14]

When a colony is dying, for whatever cause, and there are other healthy colonies nearby (as is typical in a bee yard), those healthy colonies often enter the dying colony and rob its provisions for their own use. If the dying colony’s provisions were contaminated (by natural or man-made toxins), the resulting pattern (of healthy colonies becoming sick when in proximity to a dying colony) might suggest to an observer that a contagious disease is involved. However, it is typical in CCD cases that provisions of dying colonies are not being robbed, suggesting that at least this particular mechanism (toxins being spread via robbing, thereby mimicking a disease) is not involved in CCD.

Additional evidence that CCD might be an infectious disease came from the following observation: the hives of colonies that had died from CCD could be reused with a healthy colony only if they were first treated with DNA-destroying radiation.[7]

Varroa and Israel Acute Paralysis Virus

According to a 2007 article, the mites Varroa destructor remain the world’s most destructive honey bee killer due in part to the viruses they carry, including Deformed Wing Virus and Acute bee paralysis virus, which have both been implicated in CCD.[25] Affliction with Varroa mites also tends to weaken the immune system of the bees. As such, Varroa have been considered as a possible cause of CCD, though not all dying colonies contain these mites.[26]

In September 2007, results of a large-scale statistical RNA sequencing study of afflicted and non-afflicted colonies were reported. RNA from all organisms in a colony was sequenced and compared with sequence databases to detect the presence of pathogens. The study used technology from 454 Life Sciences developed for human genome sequencing. All colonies were found to be infected with numerous pathogens, but only the Israel acute paralysis virus (IAPV) showed a significant association with CCD: the virus was found in 25 of the 30 tested CCD colonies, and only in one of the 21 tested non-CCD colonies.[7] Scientists pointed out that this association was no proof of causation, and other factors may also be involved in the disease or the presence of IAPV may only be a marker signifying afflicted colonies and not the actual causative agent. To prove causation, experiments are planned to deliberately infect colonies with the virus.[6]

The IAPV was discovered in 2004 and belongs to the Dicistroviridae. It causes paralysis in bees which then die outside of the hive. It can be transmitted by the mite Varroa destructor. These mites, however, were found in only half of the CCD colonies.[7]

The virus was also found in samples of Australian honey bees. Australian honey bees have been imported into the U.S. since 2004[6] and until recently it was thought possible that this is how the virus originally reached North America. Recent findings, however, reveal the virus has been present in American bees since 2002.[27][28]

One recently published view is that bees are falling victim to new varieties of nicotine-based pesticides;[40][41] beekeepers in Canada are also losing their bees and are blaming neonicotinoid pesticides. To date, most of the evaluation of possible roles of pesticides in CCD have relied on the use of surveys submitted by beekeepers, but it seems likely that direct testing of samples from affected colonies will be needed, especially given the possible role of systemic insecticides such as the neonicotinoid imidacloprid (which are applied to the soil and taken up into the plant’s tissues, including pollen and nectar), which may be applied to a crop when the beekeeper is not present. The known effects of imidacloprid on insects, including honey bees, are consistent with the symptoms of CCD;[42] for example, the effects of imidacloprid on termites include apparent failure of the immune system, and disorientation.[43] In Europe the interaction of the phenomenon of “dying bees” with imidacloprid, has been discussed for quite some time now.[44][45][46] It was a study from the “Comité Scientifique et Technique (CST)” which was in the center of discussion recently, which led to a partial ban of imidacloprid in France (known as Gaucho), primarily due to concern over potential effects on honey bees.[47][48][49] Consequently when fipronil, a phenylpyrazole insecticide and in Europe mainly labeled “Regent”, was used as a replacement, it was also found to be toxic to bees, and banned partially in France in 2004.[50] In February 2007, about forty French deputies, led by UMP member Jacques Remiller, requested the creation of a Parliamentary Investigation Commission on Overmortality of Bees, underlining that the honey production was decreasing by 1,000 tons a year for a decade. As of August 2007, no investigations were yet opened.[31] The imidacloprid pesticide Gaucho was banned, however, in 1999 by the French Minister of Agriculture Jean Glavany. Five other insecticides based on fipronil were also accused of killing bees. However, the scientific committees of the European Union are still of the opinion “that the available monitoring studies were mainly performed in France and EU-member-states should consider the relevance of these studies for the circumstances in their country.”[51]

In 2005, a team of scientists led by the National Institute of Beekeeping in Bologna, Italy, found that pollen obtained from seeds dressed with imidacloprid contains significant levels of the insecticide, and suggested that the polluted pollen might cause honey bee colony death.[52] Analysis of maize and sunflower crops originating from seeds dressed with imidacloprid suggest that large amounts of the insecticide will be carried back to honey bee colonies.[53] Sub-lethal doses of imidacloprid in sucrose solution have also been documented to affect homing and foraging activity of honeybees.[54] Imidacloprid in sucrose solution fed to bees in the laboratory impaired their communication for a few hours.[55] Sub-lethal doses of imidacloprid in laboratory and field experiment decreased flight activity and olfactory discrimination, and olfactory learning performance was impaired.[56] However, no detailed studies of toxicity or pesticide residue in remaining honey or pollen in CCD-affected colonies have been published so far, so, despite the similarity in symptoms, no connection of neonicotinoids to CCD has yet been confirmed.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.