More than a dozen pesticides are now banned in Oregon after 50,000 bees were found dead in a Target store parking lot earlier this month.
The bees were killed at the Target store in Wilsonville in mid-June.
Pesticide poisoning from a product known as Safari caused the bumblebee deaths, officials said, and that product is one of several now banned by the state.
A week after the Wilsonville bee deaths, hundreds of bees were also found dead around a tree in Hillsboro. City officials said the tree had been sprayed with Safari earlier in the year, but they haven't ruled Safari as the cause of the deaths.
The trees in question in both Wilsonville and Hillsboro have now received a mesh covering to make sure bees can't reach them.
To prevent another bee killing, the Oregon Department of Agriculture is also temporarily banning the use of 18 pesticide products. Pesticides containing dinotefuran can no longer be used on plants, or at least not until the ban is lifted.
ODA officials said they're acting "in an abundance of caution" in issuing the ban. Director Katy Coba said she hopes the decision minimizes the potential for more bee deaths connected to pesticide products while the state continues to investigate and gather information.
For a complete list of the products that are banned, visit http://www.oregon.gov/ODA/PEST/docs/pdf/DinotefLimitList06272013.pdf.
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