The human population is growing and agricultural production must keep up with it! Fruit and seed-set of most crops is dependent upon pollination, yet honeybees appear to be in decline. The pollination gap this has created is currently being filled by solitary bees. As humans change their landscape to produce more crops, what are the ramifications for our solitary pollinators? I study the mason bee Osmia cornifrons to answer this question. At the landscape scale, I am using historical data to document temporal and spatial range changes of this species across the Eastern Seaboard. Locally, I am placing bees in New York apple orchards that range from agricultural to natural surroundings and analyzing their pollen to quantify host-plant diversity and pesticide content. I will follow these field experiments with laboratory experiments to deduce which specific diets and pesticides are most detrimental and/or beneficial to solitary bee fitness. If we understand what conditions are most beneficial for solitary bees, we can design agriculture with them in mind, and conserve both bees and agricultural production.