July 16, 2021 | Research published in Environmental Entomology reviews the 2013 Wilsonville, Oregon mass bumblebee die-off from application of the neonicotinoid dinotefuran on 55 linden trees in a big-box-store parking lot. In that single event, the research paper estimates between 45,830 and 107,470 bumblebees from some 289– 596 colonies were killed. The coauthors said: “Our study underscores the lethal impact of the neonicotinoid pesticide dinotefuran on pollinating insect populations,” and, “It is likely that the vast majority of mass pesticide kills of beneficial insects across other environments go unnoticed and unreported.” Dinotefuran, the neonicotinoid (neonic) that killed those Oregon bumblebees, is used against fleas, thrips, tree-boring caterpillars, emerald ash borers, hemlock woolly adelgids, and in the Oregon case, aphids. Emerging scientific consensus on central causes of bee loss focuses on pesticide impacts and how they make bees more vulnerable to pathogens. As Beyond Pesticides wrote, 2019 Canadian research “found that ‘real life’ exposures to neonicotinoid insecticides impair honey bees’ ability to groom harmful mites from their bodies, thus allowing mite populations to thrive.” In addition, Beyond Pesticides has discussed the correlation, during the early 2000s, of the emergence of CCD [Colony Collapse Disorder] and severe colony losses with the spike in use of neonicotinoid pesticides, particularly delivered as seed coatings. In 2014, a study from the Harvard T.H. Chan School of Public Health showed that two neonics—imidacloprid and clothianidin—significantly harm honey bee colonies during winters. [Hatfield, Richard et al. Neonicotinoid Pesticides Cause Mass Fatalities of Native Bumble Bees: A Case Study From Wilsonville, Oregon, United States, Environmental Entomology, 50(5)1095–1104, 2021.]
