D3032: Osmia cornifrons survival after oral exposure to insecticides, flupyradifurone and sulfoxaflor

Osmia cornifrons, or the horned-face bee, is a mason bee native to northern parts of Asia, including Japan, China, Korea, and eastern Russia. They are one of the few solitary bee species to be commercially managed and were introduced to the United States in the 1970s to pollinate fruit trees. They are efficient pollinators and have high pollen fidelity, and so can greatly benefit orchard yields and enhance pollination compared to that of honey bees alone. Honey bees (Apis mellifera) are often used as surrogates for other insect pollinators when assessing the risk of new insecticides. Other bee species, however, can be more sensitive to certain pesticides, so it is also important to research the impact of novel pesticides on other bee species, such as O. cornifrons. For this study, we investigated the effect of two recently approved insecticides, sulfoxaflor and flupyradifurone, on O. cornifrons survival. Both insecticides share a similar mode of action to the neonicotinoid class, but can be effectively used against neonicotinoid-resistant pests. They may also pose a risk to beneficial pollinators, however. We orally exposed bees to sulfoxaflor or flupyradifurone at field realistic concentrations and measured survival over 4 days following exposure. We found O. cornifrons females to have higher sensitivity to these pesticides compared to similar oral exposure studies in social bees (A. mellifera and B. impatiens), but were more resistant than some other Osmia bee species. Male O. cornifrons bees were not as sensitive as females.