“Bees are dying in Europe, U.S., Asia, but not in Australia”

PATNA, TNN, Mar 15, 2010: Honeybees are fast disappearing from parts of Bihar and Nepal. So suggest reports collected by Tarumitra, which works to promote healthy environment and preservation of bio-diversity at the national level.

According to these reports, a cooperative society of Bihar’s Vaishali district engaged in apiculture, is in trouble as due to fewer honeybees, the cooperative’ honey output has nosedived. The number of boxes used here for bee keeping has come down from about 100 to less than 20.

A study published in 2010 found that bees that were fed pollen from a variety of different plant species showed signs of having a healthier immune system than those eating pollen from a single species. Bees fed pollen from 5 species had higher levels of glucose oxidase than bees fed pollen from one species, even if the pollen had a higher protein content. The authors hypothesised that CCD may be linked to a loss of plant diversity.

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. 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.

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.

The virus was also found in samples of Australian honey bees. Australian honey bees have been imported into the U.S. since 2004 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.

Recent research (2009) has found that an indicator for an impaired protein production is common among all bees affected by CCD, a pattern consistent with IAPV infection. It is conjectured that Dicistroviridae, like the IAPV, cause degradation of the ribosomes, which are responsible for protein production of cells, and that this reduced ribosomal function weakens the bees, making them more vulnerable to factors that might not otherwise be lethal.

Nosema

Some have suggested that the syndrome may be an inability by beekeepers to correctly identify known diseases such as European foulbrood or the microsporidian fungus Nosema. The testing and diagnosis of samples from affected colonies (already performed) makes this highly unlikely, as the symptoms are fairly well-known and differ from what is classified as CCD. A high rate of Nosema infection was reported in samples of bees from Pennsylvania, but this pattern was not reported from samples elsewhere.