Does insecticide exposure affect solitary bee nesting behavior?

Thanks for your interest Rainee! Short answer: yes! We want to make sure that exposure protocols follow realistic field exposure scenarios. We are focusing on neonicotinoids, which is the common class of insecticide these bees are exposed to in alfalfa. These compounds are systemic though, meaining they are expressed through the plant and calculating the exact dose to which individuals are exposed to in the field is a bit trickier than with insecticides that are directly sprayed on the plant. We know approximately the concentration of neonicotinoids expressed in pollen and nectar as well as the LD50 for our species (the insecticide dose at which 50% of the population dies). From there we can expose bees to decreasing concentrations of insecticides in the lab which will give us the range of lethal and sublethal doses and which we can compare to our known field levels. If the range of lethal doses found in the lab are way higher than known field levels, we will use concentrations that are on the higher end of field-exposure levels to keep the study ecologically relevant. We have some more details on how we intend to validate sublethal effects as well in our Method section if you are interested: https://experiment.com/projects/does-insecticide-exposure-affect-solitary-bee-nesting-behavior/methods Hope this clarifies, let me know if you have any other questions!

I wrote a long answer, but it disappeared! Bah humbug! Just read Raph's answer for now