The pesticides imidacloprid and clothianidin were tested on the orchard mason bee (Osmia lignaria) and the alfalfa leafcutter bee (Megachile rotundata) respectively, in British Columbia, Canada. These species are susceptible to pesticide exposure and ingestion both in their natural environment and when used for pollination of crops. Pesticide doses were added to the pollen provisions upon which the larvae fed, in both field and laboratory settings. We assessed lethal and sub-lethal effects, including larval mortality, time to pupation, and pupal weight. Additional sub-lethal effects will also be determined, including timing and successful emergence of adults, reproductive output and behaviours such as nest recognition, provisioning and foraging ability.