Insect pollinators collect pollen from wind-pollinated plants: implications for pollination ecology and sustainable agriculture

Current research, management and outreach programmes relevant to insect pollinator conservation are strongly focused on relationships between pollinators and insect-pollinated crops and wild plants. Pollinators also visit wind-pollinated plants to collect pollen, or for nest sites and materials, but these interactions are largely overlooked. I review documented records of bee and syrphid fly species collecting pollen from wind-pollinated plant taxa, including economically important crops, and provide the most comprehensive collation of peer-reviewed records of pollinators visiting wind-pollinated plants to date. I argue for more basic research into functional relationships between insect pollinators and wind-pollinated plants. I found over 200 visitation records for 101 wind-pollinated plant genera in 25 families, including 4 of the 12 gymnosperm families. Almost half the records (49%) were for grasses and sedges (Poales). I also identified records of bees and/or syrphid flies visiting 10 economically important wind-pollinated crop plant species, including three major grain crops (rice, corn, and sorghum). Most records (70%) were from indirect pollen analysis from hives, nest cells or insect bodies, highlighting the need for more direct observational studies of plant-pollinator interactions. Insect pollinator communities require resource diversity to persist in a landscape. Hence, researchers and land managers aiming to identify links between pollinators and ecosystem function should also consider broader interactions beyond the standard traits of the entomophily syndrome.