Synergistic effects of pesticides and parasitic fungi and worsening decline of honeybeesThe decline of the honeybee attracted worldwide attention in 2007. Investigations carried out by the Institute of Science in Society implicated a synergistic interaction between the recent widespread use of new pesticides (including Bt toxin from GM crops) and fungal infections <1, 2> (Parasitic Fungus and Honeybee Decline , Parasitic Fungi and Pesticides Act Synergistically to Kill Honeybees?, SiS 35). Sub-lethal levels of neonicotinoid pesticides act synergistically with parasitic fungi 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. That information was transmitted through a written question to the European Parliament <3>.
Last year’s decline was serious enough and described as “beepocalypse now” by a news report <4>. According to the US Department of Agriculture one mouthful in three of the foods we eat directly or indirectly depend on pollination by honeybees <5>. Most fruit and many vegetables would disappear from our diet along with an immediate shortage of meat due to the loss of forage. This winters’ bee loss was 34 percent, up from the 25 percent the previous year <6>.
The decline is attributed to ‘Colony Collapse Disorder’ (CCD), most likely to be multi-factorial. The main suspects include pesticides, parasites, viruses, radiation from cell phone transmitters <7-9> (Mystery of Disappearing Honeybees, Requiem for the Honeybee, Mobile Phones and Vanishing Bees, SiS 34) and even brood temperature <10>. The impact of sub-lethal levels of pesticides on the immune system of the bee leads to synergistic infection of the bees by fungal parasites. In addition, the behaviour of the bees is frequently modified leading to confusion in foraging and failure to return to the hive.
Organic farming practices that retain more natural habitats and avoid the use of chemical pesticides should provide environments that serve as honeybee sanctuaries from the ravages of CCD. There are scientific studies showing that agricultural landscapes with organic crops are far superior environments for both honey- and bumblebees <11, 12>. It would be prudent to create organic bee sanctuaries as widely and as soon as possible.
http://www.i-sis.org.uk/honeyBeeOrganicFarming.php