[VIDEO] Pestcides suspected in big bumblebee die-off in OR WILSONVILLE, Ore., June 22 (UPI) -- A mass die-off of bumblebees in Wilsonville, Ore., blamed on pesticides, has reached 50,000 of the insects, say scientists who are investigating the deaths. The (Portland) Oregonian reported Saturday a second city, Hillsboro, has discovered hundreds of dead bumblebees following the die-off in a Target parking lot in Wilsonville in recent days. "We take it seriously," Hillsboro spokesman Patrick Preston said, Saturday. We recognize the importance of bees. Preston confirmed that trees in downtown Hillsboro were sprayed in March with the same pesticide, Safari, that was used in Wilsonville to kill aphids. State agricultural officials say the pesticide caused the bumblebee deaths in Wilsonville, where spraying took place June 15. The Xerces Society, an invertebrate conservation group that has been investigating the bumblebee die-off, said it is likely the bees were members of more that 300 wild colonies, KGW-TV, Portland, reported. Each of those colonies could have produced multiple new queens that would have gone on to establish new colonies next year. This makes the event particularly catastrophic," Xerces Society biologist Rich Hatfield said in a release. Efforts were under way to place bee-proof netting over trees that had been sprayed in an attempt to prevent more bees from dying, the TV station said.