COMMON AND WIDESPREAD INSECTS ARE IN DECLINE IN THE AMERICAN WEST. THESE LOSSES ARE ONLY PARTIALLY UNDERSTOOD BUT ARE ALMOST CERTAINLY A COMBINATION OF FACTORS THAT INCLUDE HABITAT LOSS, PESTICIDE USE, AND CLIMATE CHANGE. UNDERSTANDING THE CONTRIBUTIONS OF THESE DIFFERENT ANTHROPOGENIC STRESSORS TO INSECT DECLINES IS CRITICAL FOR FORECASTING FUTURE POPULATION TRAJECTORIES AND DISRUPTION TO ECOSYSTEM SERVICES. WITH A BETTER UNDERSTANDING OF THESE STRESSORS, WE CAN DEVELOP BETTER CONSERVATION STRATEGIES TO PRESERVE THE CRITICAL ROLE OF INSECTS IN ECOSYSTEMS AND THEIR PRICELESS BIODIVERSITY.TO UNDERSTAND CURRENT POPULATION TRENDS AND HOW MANAGEMENT CAN EFFECTIVELY REVERSE THEM, THIS PROJECT WILL UTILIZE BOTH OBSERVATIONAL AND EXPERIMENTAL RESEARCH. WE WILL CONTINUE THE MONITORING OF BUTTERFLIES IN NORTHERN CALIFORNIA AND CONDUCT EXPERIMENTS TO TEST THE IMPACTS OF WARMING TEMPERATURES AND PESTICIDES. THESE TWO DIFFERENT DATA TYPES ARE OFTEN VIEWED AS OPPOSING, OBSERVATIONAL DATA BEING TOONOISY TO UNDERSTAND BIOLOGICAL MECHANISMS AND EXPERIMENTS BEING TOO UNREALISTIC TO APPLY TO THE FIELD. HERE, WE VIEW THEM AS BOTH BEING INTEGRAL FOR UNDERSTANDING DECLINES AT DIFFERENT SCALES AND WILL UNITE THEM USING SIMULATIONS. USING THIS APPROACH, WE CAN EXPLORE PROCESSES MEASURED IN THE LAB AND CAN SCALE THEM UP TO THE PATTERNS WE OBSERVE IN THE FIELD. CRITICALLY, WE WILL ALSO CHANGE THE PARAMETERS OF THE SIMULATION TO TEST THE EFFECTIVENESS OF DIFFERENT TYPES OF CONSERVATION ACTION.