A novel laboratory method for simulating pollinator exposure to particulate matter

Abstract

Abstract Deposition of particulate matter (PM) from a variety of sources onto pollinator habitat is a largely unexplored source of risk to pollinators. Synthetic steroid growth promoters, antibiotics, and multiple pesticides have been detected in fugitive beef cattle feedyard PM. Subsequently, many of these chemicals determined to be associated with PM have been detected on flowers near beef cattle feedyards, as well as bees visiting those flowers. Therefore, there is a need to assess risk to pollinators posed by deposition of PM and agrochemical-laden PM, both in the field and the laboratory. Unfortunately, there are no established laboratory methods for simulating PM exposure or toxicity associated with contaminated PM. Herein we describe development and utilization of a PM circulation system that can be employed in the laboratory under controlled conditions. Two model organisms (honeybees (Apis mellifera) and mason bees (Osmia lignaria)) were exposed to agrochemical-free PM in the circulator system, and post-exposure mortality was compared with controls. No significant differences in mortality between exposed and control bees were observed. These results confirm the validity of these methods for use in laboratory-controlled PM exposure experiments, and offer a source of positive and negative control groups for laboratory and field experiments examining exposure of pollinators to potentially toxic chemical-laden PM.