Dispensers for entomovectoring: For every bee a different type?

Abstract

To load pollinators with supplemental pollen or a biocontrol organism (BCO) in an efficient way, the use of a suitable dispenser is crucial. Over the past years, multiple studies have been conducted to optimize dispensers for honey bees, bumble bees and mason bees and test their potential for application with the entomovector technology. Research on dispensers for honey bees started by testing simple one-way dispensers, previously used to load pollinators with pollen, but they soon proved to be inefficient in loading the bees with a BCO. More efficient two-way dispensers, where entrance and exit ways are separated, were developed and improved, ultimately leading to an efficient model that was suitable for commercial use, the BeeTreat dispenser. As behavioral differences between honey bees and bumble bees proved to be a problem in attempts to load bumble bees using the honey bee dispensers, dedicated models were developed to achieve a sufficient loading and use bumble bees as a vector for BCO delivery. Today, two commercial dispensers are available for bumble bees. While the development of dispensers for mason bees is still at an earlier stage, progress on optimizing the dispenser model shows promising forthcoming results. Future effort should be devoted, but not limited to, increasing our knowledge on the pollination and entomovectoring potential of solitary bee species, like those of the genus of Osmia. Alongside with the continued improvement of the dispenser models, the main focus of the research should shift towards improving the powder formulation which can be loaded in the dispenser to increase the efficiency of the entomovector technology.