An estimated 25,000 bumblebees, as well as honeybees and beetles, were found littering the ground Target parking lot in Wilsonville, Oregon, according to a press release from the Xerces Society for Invertebrate Conservation, an insect conservation group based in Portland. Rich Hatfield, a conservation biologist with the Xerces Society, says that he began receiving calls from shoppers on Monday about the dead bees in the parking lot and he arrived to see that the bees “were literally falling out of the trees,” he said in a statement.

“To our knowledge this is one of the largest documented bumble bee deaths in the Western U.S. It was heartbreaking to watch,” Hatfield said.

The Oregon Department of Agriculture is investigating the cause of tragic loss, but pesticides are suspected. The Oregon Public Broadcasting (OPB) reported that a landscaping company had used an insecticide called Safari on dozens of European linden trees in the retailer’s parking lot. Safari is a class of neonicotinoid pesticide that is highly toxic to bees. In fact, in January 2013, the European Food Safety Authority stated that neonicotinoids pose an unacceptably high risk to bees.

Scott Hoffman Black, Executive Director of the Xerces Society, says that spraying the treese while they were in bloom caused the error: “Evidently they didn’t follow the label instructions. This should not have been applied to the trees while they’re in bloom,” he told OPB, due to the bees feeding on the trees’ nectar and pollen. The linden treese themselves may also have been poisonous.

Established in 1971, The Xerces Society is a nonprofit that protects wildlife through the conservation of invertebrates and their habitat. “Over the past three decades, we have protected endangered species and their habitats, produced ground-breaking publications on insect conservation, trained thousands of farmers and land managers to protect and manage habitat, and raised awareness about the invertebrates of forests, prairies, deserts, and oceans.”

The mass bee death unfortunately coincides with National Pollinator Week, June 17-23, which is designed to draw attention to the devasting decline of bee populations. Bees are responsible for up to $15 billion in U.S. agriculture and impacts vitral crops including fruits, vegetables, and nuts.

“Pollinating animals, including bees, birds, butterflies, bats, beetles and others, are vital to our delicate ecosystem,” according to the Pollinator Partnership, “supporting terrestrial wildlife, providing healthy watershed, and more. Therefore, Pollinator Week is a week to get the importance of pollinators’ message out to as many people as possible. It’s not too early to start thinking about an event at your school, garden, church, store, etc. Pollinators positively effect all our lives- let’s SAVE them and CELEBRATE them!”

Have you seen evidence of the bee population decline in your area? — Casandra Armour