A protein-based marker method to quantify foraging patterns of Osmia cornifrons (Radoszkowski) in tree fruit ecosystem

Foraging patterns of bee species in tree fruits such as apple and cherry should be understood for proper placement of nest sites and to ensure adequate pollination. Field and laboratory studies were conducted to quantify the foraging patterns of Osmia cornifrons (Radoszkowski) (Megachilidae, Hymenoptera) with an immunomarking method in commercial cherry and apple orchards in Pennsylvania. Adults of O. cornifrons were self-marked with chicken egg-white protein powder from a dispenser nest placed at the center of the study orchards at early bloom. Flower samples were collected from randomly selected trees (n= 30) located at different distances from the nest. Flowers were analyzed for the presence of immunomarker protein with enzyme-linked immunosorbent assay. Foraging patterns were determined by calculating the distance and direction of marked flowers from the nest. Marked flowers were found out to the maximum of 55 m and marking in flowers dropped of rapidly beyond 40 m. Fruit density per limb cross-sectional area (cm²) on the same sample trees (in cherry orchard) correlated well with distance and proportion of protein-marked flowers from the bloom samples, and was significantly higher than the control orchard, indicating valuable pollination services of O. cornifrons in increasing fruit yield. O. cornifrons adults are efficient tree fruit pollinators, but their foraging range is limited requiring strategic nest placement to ensure proper orchard pollination.