|New labeling for some plants |
sold by The Home Depot alerts the
consumer to neonicotinoid-treated
As one of the first studies to look at honey bee colony health over multiple seasons, the results were more rigorous than previous research. They did showed a significant negative effect on colony survivorship as dosage increased; however the lowest, field-realistic dose showed no significant impact on key bee health indicators, foraging or winter survivorship. The major impact of higher imidacloprid exposure were increased broodless periods, caused by weak queens during late summer. Such effects could lead to lowered overwintering survival, a character of CCD.
Nevertheless, the authors conclude that while short term exposure to high imidacloprid levels (represented by 100 part per billion dosages in this study) in agricultural settings does occur, it is not likely to occur continuously throughout a crop cycle. Also, data from the study showed that bees were efficient in metabolizing imidacloprid, so that short term spikes in insecticide levels in nectar were likely to be quickly diluted and eliminated by the bees. They concluded that while imidacloprid might be a contributing factor to some overwintering losses in bees, seed treated crops in particular were likely to have negligible effects on honey bee colony health.
In the ongoing debate over bee health, this is one piece of good news for pesticide manufacturers and users; but it will not be the final word. And it should not justify anything less than the utmost caution for pesticide applicators when they use neonicotinoid insecticides.