BUMBLE BEES ARE AN IMPORTANT GROUP OF POLLINATING INSECTS THAT AID IN THE PRODUCTION OF MANY AGRICULTURAL PRODUCTSINCLUDING MOST BERRIES, APPLES, MELONS, TOMATOES, AND FORAGE CROPS. HOWEVER,DECLINES IN BUMBLE BEE POPULATIONS HAVE BEEN RECORDED ACROSS THE WORLD. OF THE MANY THREATS THAT BUMBLE BEES FACE, THE IMPACT OF CLIMATE IS STILL NOT FULLY UNDERSTOOD. WHILE A GENERAL INCREASE IN GLOBAL TEMPERATURES OVER THE NEXT CENTURY MIGHT IMPACT BUMBLE BEE POPULATIONS, THE RECENT INCREASE IN THE FREQUENCY, INTENSITY, AND DURATION OF EXTREME WEATHER EVENTSASSOCIATED WITH CLIMATE CHANGE, SPECIFICALLYHEAT WAVES, REPRESENTS A CLEAR THREAT BUMBLE BEES WHICH ARE ADAPTED TO LIVE IN RELATIVELY COOL, TEMPERATE AREAS. AS HEAT WAVES BECOME MORE COMMON AND REACH HIGHER TEMPERATURES, THEY MAY TO REDUCE THE SUITABILITY OF ENTIRE REGIONS TO BUMBLE BEES AND, IN DOING SO, THREATEN THE POLLINATION SERVICES THAT BUMBLE BEES PROVIDE.TO ADDRESS THIS CONCERN, THIS PROJECT AIMS TO MEASURE THE IMPACT OF HEAT WAVES ON BUMBLE BEES TO DETERMINE, HOW HOT IS TOO HOT? TO DO THIS, I WILL USE A VARIETY OF EXPERIMENTAL AND COMPUTATIONAL APPROACHES IN BOTH THE LABORATORY AND IN THE FIELD TO MEASURE HOW INCREASING TEMPERATURES IMPACT BUMBLE BEE COLONIES AND THE POLLINATION SERIVCES THEY PROVIDE. IN DOING SO, I WILL BE ABLE TO ESTIMATE NOT ONLY WHICH TEMPERATURES ARE UNSUITABLE FOR BUMBLE BEES, BUT USE CLIMATE MODELS TO PROJECT THE CROPS AND REGIONS WITHIN CALIFORNIA, THE STATE WITH AMONG THE MOSTBUMBLE BEE DEPENDENT AGRICULTURE, ARE MOST VULNERABLE TO HEAT WAVES AND THEIR IMPACTS ON BUMBLE BEES.IN COMPLETING THIS WORK, WE WILL HAEV A BETTER UNDERSTANDING OF HOW, WHERE, AND WHEN BUMBLE BEES WILL BE THREATENED BY HEAT WAVES, AND CAN PROVIDE MITIGATION TECHNIQUES TO GROWERS TO HELP ENSURE THE ADEQUATE POLLINATION OF THEIR CROPS. ADDITIONALLY, THIS PROJECT WILL ALLOW US TO ESTIMATE HOW CLIMATE LOOKS TO SHAPE THE SUITABILITY OF OUR LANDSCAPES FOR IMPORTANT INSECTS LIKE BUMBLE BEES IN THE NEAR FUTURE - PROVIDING AN EARLY WARNING THAT WE CAN USE TO PLAN MORE RESILIENT AGRICULTURAL SYSTEMS IN THE FACE OF A HOTTER CALIFORNIA.