ABS 2022
Extra, extra, buzz all about it: anther chemical cues signal bees to buzz for pollen.
Abilene R. Mosher1, Thomas Eltz2, Daniel R. Papaj3, Stephen Buchmann3, Avery L. Russell1. 1Missouri State University, Springfield, MO, United States; 2University of Bochum, Bochum, Germany, Germany; 3University of Arizona, Tuscon, AZ, United States

Plants often provide cues eliciting pollinator behaviors that benefit the plant, but which also may benefit the pollinator. Cues directing pollinators to floral nectar rewards are common and enhance pollination, yet the function of cues associated with pollen rewards is poorly understood. Here we investigated the function and identity of cues eliciting a widespread bee pollen foraging behavior termed floral buzzing. Using crude solvent extracts and gas coupled mass spectrometry (GC-MS), we found chemical cues specifically associated with anthers (the male reproductive flower part), mediated floral buzzing. Extracts volatilized in a time series revealed that the cues eliciting buzzing have low volatility, suggesting they elicit buzzing only at close range. Our results suggest anther cues benefit plants by stimulating bees only when close to the reproductive organs (potentially enhancing pollination), but also benefit bees by eliciting pollen foraging only on anthers. Finally, we discuss the unusual nature of these anther cues, which seem to serve as a private channel signaling anther presence to bees. In ongoing work, we continue to characterize the specific chemistry involved.