Variation in nutrient composition of bee pollen from Apis mellifera colonies under crop drought stress

Interaction and coevolution between plants and pollinators dates back to the evolution of flowering plants, and ever since there has been a successful mutualism but in the recent past this interdependent relationship is under peril. The ongoing threat to honeybees strongly relates to nutritional deficiencies resulting from reduced pollen and nectar diversity in their diet, defining the importance of native flora and other pollinator plants in our ecosystem. In addition, ongoing climatic changes are causing unprecedented changes to temperature and precipitation patterns. Crops grown in such less than ideal conditions compromise the expression of physiologically expensive floral traits, such as flower size, floral longevity etc. influencing pollinator attraction. However, there is little information on the role of crop abiotic stress on quantity and quality of pollen grains but these can directly affect the nutrients that honeybees acquire from crops. Preliminary results indicate a significant reduction in the quantity of pollen brought into colonies near drought stressed fields. A comparison of bee pollen collected from hives during and after crop bloom indicate higher levels of P-coumaric content in hives located near irrigated stressed fields. Studies describing the identity and bloom time of non-crop flowering plants and detailed analyses of pollen metabolome are underway. The importance of crop physiological status and diversity in pollen diet in providing a balanced nutrition for pollinators are discussed.