Evaluating the persistence of fluorescent and protein powders on adult blue orchard bees, Osmia lignaria (Hymenoptera: Megachilidae), for mark-capture studies

Abstract

The managed, solitary bee, Osmia lignaria Say, is an efficient pollinator of orchard crops. One limitation to their commercial success is high dispersal of populations away from orchards, resulting in low establishment in provided nest cavities even when optimal pollination is achieved. While exact causes for dispersal are unknown, many existing theories remain untested due to complications with evaluating O. lignaria establishment in field settings. We describe relatively simple and reliable methods for passively marking O. lignaria with egg albumin and casein powdered proteins combined with orange fluorescent powder as they emerge from cocoons. Marked adults were examined microscopically at 0, 3, 6, 9, 12, 15, and 18 days after emergence for the fluorescent powder followed by an anti-albumin and anti-casein enzyme-linked immunosorbent assay to detect the protein powders. The orange powder and egg albumin were highly persistent on adults throughout the 18-day study, suggesting the utility of these markers for studying dispersal and retention of O. lignaria in the field.