Solitary Wild Bees Harmed by Neonicotinoid Pesticides Applied by Soil Drenching

March 2, 2021 | Populations of solitary ground nesting bees decline after exposure to neonicotinoid insecticides, according to a study in Scientific Reports. In addition to ground nesting bees, neonicotinoids have been shown to harm butterflies, hummingbirds, songbirds, aquatic species and mammals, including humans. As independent science continues to look beyond the effects of these systemic chemicals on honeybees and bumblebees, advocates maintain that it has become increasingly clear that the high hazards presented by neonicotinoids necessitate their complete elimination. “Farmers need to protect their crops from pests, but they also absolutely need to protect pollinators from the unintended effects of pesticides,” said study coauthor Susan Willis Chan, PhD. “The data on this particular [neonicotinoid] product are so clear that there’s really no question about what has to happen. We have to find something else.” Researchers focused their investigation on how various systemic pesticides affect the hoary squash bee (Eucera pruinosa), a ground nesting bee found throughout North America that feeds entirely on pollen from cucurbits (including squash, cucumber, pumpkin, gourds, etc). The hoary squash bee provides essential pollinator services for these crops throughout the U.S. and Canada. Neonicotinoids and other systemic insecticides are often applied in an attempt to manage cucumber beetles, which consume these crops and can spread disease to susceptible plants. [Chan, Willis et al. Population decline in a ground-nesting solitary squash bee (Eucera pruinosa) following exposure to a neonicotinoid insecticide treated crop (Cucurbita pepo). Scientific Reports. 11:4241, 2021.]