Karl Foord - Extension Educator, Horticulture
The United States Environmental Protection Agency (EPA) has instructed the manufacturers to change the labels on those chemicals that have been designated as Pollinator Toxic Pesticides (PTP). One educational piece that has been released describes the changes (Exhibit 1). The label will contain a Bee Hazard Icon to alert users that this is a PTP (Exhibit 2).
The old label language for pesticides toxic to bees was as follows:
"For crops in bloom, do not apply this product to target crops or weeds in bloom."
The new language is as follows:
"Do not apply (product) while bees are foraging. Do not apply (product) to plants that are flowering. Only apply after all flower petals have fallen off."
The language is more extensive for commercial users and lists conditions under which one might apply chemicals even though bees are present. The main difference between old and new labels appears to be the last sentence stating that the product cannot be applied until all of the petals have fallen off the plant.
Exhibit 1:EPA Advisory Box
Exhibit 2: Bee Hazard Icon
At least one significant factor motivating the label changes by the EPA was the move by the European Commission to restrict the use of three neonicotinoids (clothianidin, imidacloprid and thiametoxam) within the European Union. This would be for purposes of seed treatment, soil application and foliar treatment on bee attractive plants and cereals. The member states failed to generate a majority either for or against this proposal and so the decision went to the Commission.
As you might expect, there are those who felt that the move by the EPA fell significantly short of what was required to protect pollinators. The science behind this controversy is no doubt complicated. Traditional experimentation involves setting up experiments where all factors but the one under interest are controlled permitting a clear picture of the effects of this one factor. However, under field conditions it is difficult if not impossible to control all factors in this way and one is left to entangle interactions. For example, there is research demonstrating that the interaction between the neonicotinoid imidacloprid and Nosema (a gut fungus causing dysentery) hampered bees ability to sterilize colony and brood food (Alaus et. al. 2010). This effect was not seen in the control or the single imidacloprid or Nosema treatments.
Even though European Union members failed to achieve a majority vote, the commission still chose to restrict use. On the other hand the U.S. EPA chose to modify labeling language and revisit the issue in 2018 when the registration of these chemicals is subject to review.
Both entities had access to the same research findings. The difference in reaction may be a philosophical one. The European Commission took the position of, given the facts the safety of these chemicals needs to be demonstrated before their use will be reinstated. The U.S. EPA took the position perhaps of, given the facts the damage of these materials must be more definitively demonstrated before their use will be restricted.
Given that we live in the U.S. we have inherited the latter philosophy. However, as a gardener I will be keenly aware of the potential impact of neonicotinoids and only use them on non-flowering plants and only under extreme circumstances, if even that.
C. Alaus et. al. Interactions between Nosema microspores and a neonicotinoid weaken honeybees (Apis mellifera). Environmental Microbiology (2010) 12(3), 774-782.