To: tejek who wrote (784870 ) 5/15/2014 5:32:24 AM From: Bilow Read Replies (2) | Respond to Hi tejek; Re: "Further, the study put to rest the notion that parasites are contributing to CCD. Discover explains When CCD first emerged in honeybee colonies in the mid 2000s, N. ceranae was put forward as a possible cause. ";Subsequent research in Europe, however, has suggested N. ceranae was widespread in many areas before CCD and is not associated with the phenomenon. "Although other studies have suggested that pesticides, particularly neonicotinoids, cause bees to become more susceptible to mites or other parasites that then kill off the bees, today’s study found that bees in the CCD hives had the same levels of parasite infestation as the control colonies. ";...no consistent pattern in pesticide levels between healthy and CCD-affected colonies when pollen, bees, and beeswax were tested for the presence of 170 pesticides. The most commonly found pesticide in that study was coumaphos, which is used to treat honey bees for Varroa mites . The pesticide class neonicotinoids (clothianidin, thiamethoxam, and imidacloprid) has been accused of being the cause of CCD. The neonicotinoids were developed in the mid-1990s in large part because they showed reduced toxicity to honey bees , compared with previously used organophosphate and carbamate insecticides. In 2008, Germany revoked the registration of the neonicotinoid clothianidin for use on seed corn after an incident that resulted in the die-off of hundreds of nearby honey bees colonies. Investigation into the incident revealed that the die-off was caused by a combination of factors , including the failure to use a polymer seed coating known as a "sticker": weather conditions that resulted in late planting of corn while nearby canola crops were in bloom, attracting honey bees; use of a particular type of air-driven equipment used to sow the seeds, which blew clothianidin-laden dust off the seeds and into the air as the seeds were ejected from the machine into the ground; dry and windy conditions at the time of planting, which blew the dust into the nearby canola fields where honey bees were foraging; and a higher application rate than had been authorized was used to treat for a severe root worm infestation. Several studies that reported a negative impact on honey bees by neonicotinoids relied on large, unrealistic doses and gave bees no other choice for pollen, and therefore did not reflect risk to honey bees under real world conditions. Nor have the studies demonstrated a direct connection or correlation to CCD. ars.usda.gov
