POLLINATORS SUCH AS BUMBLEBEES ARE CRITICAL FOR MAINTAINING HEALTHY FOOD SYSTEMS, YET THEIR POPULATIONS ARE THREATENED BY ENVIRONMENTAL STRESSORS, ESPECIALLY PESTICIDE USE. WHILE MANY STUDIES HAVE DOCUMENTED DIRECT EFFECTS OF PESTICIDES ON BEE SURVIVAL, MUCH LESS IS KNOWN ABOUT HOW PESTICIDES INFLUENCE THE DEVELOPMENT OF DIFFERENT CASTES WITHIN A COLONY (QUEENS, WORKERS, AND MALES) THAT ARE ESSENTIAL FOR LONG-TERM POLLINATOR HEALTH. BECAUSE ALL CASTES SHARE THE SAME GENETIC BACKGROUND, STRESS FROM PESTICIDES MAY DISRUPT THEIR DEVELOPMENT IN LINKED WAYS, REDUCING THE FLEXIBILITY AND RESILIENCE OF COLONIES. UNDERSTANDING THESE HIDDEN EFFECTS IS VITAL NOT ONLY FOR PROTECTING POLLINATORS BUT ALSO FOR ENSURING STABLE CROP PRODUCTION, ECOSYSTEM SERVICES, AND FOOD SECURITY.THIS PROJECT WILL STUDY HOW COMMON PESTICIDES AFFECT THE GROWTH, APPEARANCE, AND GENE ACTIVITY OF BUMBLEBEES. COLONIES WILL BE RAISED IN THE LAB, GIVEN FOOD WITH SAFE BUT REALISTIC PESTICIDE LEVELS, AND CAREFULLY MEASURED TO SEE HOW THEIR SEX RATIOS, BODY SIZES, AND GENE EXPRESSION PATTERNS CHANGE. MODERN TOOLS INCLUDING DIGITAL IMAGING, GENETIC SEQUENCING, AND ARTIFICIAL INSEMINATION WILL ALLOW US TO DETECT SUBTLE SHIFTS IN HOW BEES DEVELOP UNDER STRESS. BECAUSE BUMBLEBEES ARE MAJOR CONTRIBUTORS TO CROP POLLINATION, THIS RESEARCH WILL PROVIDE SCIENCE-BASED GUIDANCE FOR AGRICULTURE AND CONSERVATION, SUPPORTING FOOD PRODUCTION, POLLINATOR HEALTH, AND ENVIRONMENTAL SUSTAINABILITY. OUTCOMES WILL ALSO ADVANCE UNDERGRADUATE TRAINING IN AGRICULTURAL SCIENCE AND STRENGTHEN COMMUNITY AWARENESS OF POLLINATOR ISSUES.