Honeybees have been disappearing worldwide. (1) Across the United States, beekeepers have been losing 30 to 90% or more of colonies in a "colony collapse disorder" (CCD) that's causing huge economic losses not only to beekeepers but also to fruit and vegetable growers. CCD has been reported from Germany, Switzerland, Spain, Portugal, Italy, Greece, and the UK. Many believe that when the honeybee disappears, our species will soon follow.

The most important single factors identified by the Institute of Science in Society (http://www.i-sis.org.uk), in CCD were sub-lethal levels of insecticides, (2) in particular, a class of new systemic neonicotinoid pesticides widely used to dress seeds and in sprays on crops, (3) and microwave radiation from wireless telephone transmitters and base stations. (4)

Sub-lethal levels of pesticides, including the Bt biopesticides produced in genetically modified (GM) crops covering some 30 percent of the global area, disorientate the bees, making them behave abnormally, and compromise their immunity to infections.

A report in the LA Times (5) suggested that a single cell parasitic fungus, Nosema ceranae , may be responsible for CCD, though the experts involved said the results are "highly preliminary".

A new review from ISIS (6) presented compelling evidence that sub-lethal levels of neonicotinoid pesticides, particularly imidacloprid, act synergistically with parasitic fungi such as Nosema in killing insects pests. Fungal spores, widely used as biocontrol agents are applied in sprays and baits, and when delivered in suspension with sub-lethal levels of pesticides are much more effective in killing insects.

Equally, Bt biopesticides enhance the killing power of parasitic fungi synergistically. Purified Bt Cry1Ab toxin killed Nosema infected borer larvae at one-third the dose required for killing the uninfected larvae. Bacillus thuringiensis kurstaki (the natural soil bacteria producing the Bt biopesticides) in commercial (Dipel) formulations killed Nosema pyrausta infected cornborer larvae at a dose 45 times lower than that killing the uninfected larvae.

Regulators have allowed the widespread deployment of systemic neonicotinoid pesticides neonicotinoids based on assessments of lethal dose in bees of the pesticides alone, ignoring clear evidence that sub-lethal pesticide levels act synergistically with fungal parasites in killing insects. The honeybees may well be succumbing to such synergistic effects. There is every reason to eliminate the use of all pesticides that act synergistically with parasitic fungi, and all Bt crops should be banned for the same reason.

Will the European Commission take the appropriate measures to halt the colony collapse of the honeybees?

This would include banning Bt crops and systemic neonicotinoid pesticides while their synergistic action in killing honeybees in combination with parasitic fungi and other infections are thoroughly investigated.

References

(1) Reported in Killing Bees series, Science in Society 34 , 2007; Institute of Science in Society ( www.i-sis.org.uk ); magazine pdf and fully referenced members' versions of articles enclosed

(2) Ho MW and Cummins J. Mystery of Disappearing Honeybees , Science in Society 34 , 35-36, 2007.

(3) Cummins J. Requiem for the Honeybee , Science in Society 34 , 37-38, 2007.

(4) Ho MW. Mobile Phones and Vanishing Bees , Science in Society 34 , 34, 2007.

(5) "Experts may have found what's bugging the bees", Jia-Rui Chong and Tomas H. Maugh II, LA Times, 26 April 2007, http://www.latimes.com/news/la-sci-bees26apr26,0,7437491.story?track=mostviewed-storylevel

(6) Cummins J. Parasitic Fungi and Pesticides Act Synergistically to Kill Honeybees? ISIS Report 7 June 2007, http://www.i-sis.org.uk/Parasiticfungi.php