The Oregon Department of Agriculture estimates 25,000 bees are dead after feeding on blooms of linden trees that were treated with dinotefuran earlier in June, leading to a temporary ban on the pesticide, announced Thursday.
The ODA has determined the application of dinotefuran – which is part of a group of pesticides known as neonicotinoids – was directly related to the bee deaths. The application was originally intended to control aphids.
In implementing a temporary restriction on the pesticide, ODA said it’s “in abundance of caution” to avoid similar large bee kills.
ODA Director Katy Coba said the ban will be in effect “until such time as our investigation is completed and we have more information.” Specifically, the ODA is allowed to enforce the ban for 180 days, after which time ODA is expected to complete its investigations.
The investigations will determine if the pesticide applications were in violation of state or federal laws.
The ODA restriction focuses on ornamental, turf, and agricultural pesticide products that are used by both professional applicators and homeowners. Products with the active ingredient dinotefuran registered in Oregon for other uses, such as flea and tick control on pets or home ant and roach control, are not affected by the restriction. ODA’s concern is focused on those uses that may impact pollinators.
Officials have also covered the treated trees with netting to prevent other bees from returning to the trees’ blooms.
Concern about bee health has been ongoing in both the U.S. and the E.U., where European Commission officials earlier this year instigated a full ban for three pesticides classified as neonicotinoids – clothianidin, thiametoxam and imidacloprid — on fears that the pesticides were harming pollinators.
The ban, which will be effective December 1, 2013, prohibits the sale and use of seeds treated with the three neonicotinoid pesticides in question, and restricts the use of the products to professionals.
The USDA has avoided issuing any similar enforcements, but has completed a joint study with the Environmental Protection Agency to address increasing incidences of bee deaths. The study found several factors have been contributing to bee decline, and categorized the issue as a “complex problem.”