Debunking wasp pollination: Wasps are comparable to bees in terms of plant interactions, body pollen and single‐visit pollen deposition

• Published in: Ecological entomology 2024-08, Vol.49 (4), p.569-584
• Main Authors: Borchardt, Kate E., Holthaus, Danielle, Soto Méndez, Paola A., Toth, Amy L.
• Format: Article
• Language: English
• Subjects: Accuracy; Apidae; Bees; body pollen carriage; Bombus impatiens; Colletidae; Deposition; Ecological niches; Environmental factors; Indigenous plants; Indigenous species; Introduced plants; Plant communities; Plant reproduction; Plant species; Plants (botany); plant–insect interactions; Polistes fuscatus; Pollen; Pollination; Pollinators; single‐visit deposition; Solidago canadensis; Vespidae; wasps
• ISSN: 0307-6946; 1365-2311
• DOI: 10.1111/een.13329

Wasps are understudied in their contribution to pollination services. In order to better understand the ecological contribution of wasp communities to plant pollination, we conducted three studies to compare bees and wasps by (1) the plant communities visited in agricultural and prairie environments, (2) body pollen composition as an indirect measure of pollination and (3) a single‐visit deposition study as a direct measure of pollination in the plant species complex Solidago canadensis. We found wasps visit a distinct early‐blooming exotic plant community from bees but have overlapping use of late‐blooming native plants and similar network interaction metrics. This suggests wasps may fill an ecological niche distinct from bees, while also serving as common native plant visitors. We also found that body pollen density and pollen fidelity in four and five (out of six) wasp families, respectively, were comparable to or greater than the bee family Colletidae. Three wasp families also showed comparable to or greater visit fidelity than two (out of five) bee families examined. These results suggest wasps may carry and potentially deliver substantial pollen to specific plants. In addition, controlled single‐visit deposition revealed the paper wasp Polistes fuscatus deposits a similar amount of pollen grains as the bumble bee Bombus impatiens, suggesting surprisingly high pollination efficiency that warrants further investigation. Our multi‐pronged study shows the importance of investigating the role of wasps as pollinators, especially by focusing on direct plant‐pollination metrics to determine wasp pollination efficacy. We challenged historical assumptions by comparing bees and wasps by (1) their role in a community, (2) body pollen carriage and (3) single‐visit deposition on the plant species complex Solidago canadensis. We found bees and wasps (1) overall visit different plant communities, (2) have comparable body pollen carriage in some families and (3) deposit similar amounts of pollen on the plant species complex S. canadensis. We conclude it is important to include wasps in pollination studies and to further investigate their role as pollinators using direct plant‐pollination metrics.