Pollen preferences among the bee species visiting apple (Malus pumila) in New York

Abstract

Maintaining a diverse and abundant wild bee community is essential for sustainable agricultural pollination, especially in crops in which wild bees are effective pollinators. Many land managers have an economic interest in encouraging healthy wild bee populations, but it is not always clear how to accomplish this. In apple orchards, wild bees play a critical role as pollinators, but are active before most forbs begin to flower. To investigate which flowering plant species might serve as alternative pollen hosts for the most abundant wild bee species collected in eastern apple orchards, we analyzed the pollen carried by 15 wild bee species and 1 managed bee species (Apis mellifera) collected during apple bloom. We identified the pollen grains carried by these bees and found that the majority of alternative pollen hosts for apple visitors are early blooming tree species, including six other tree genera. This may partly explain why the presence of forest fragments is an important predictor of bee abundance and species richness in New York apple orchards.