The Buzz of Inconsistency: Pollinator Potential vs. Research Effort

Abstract

Pollinator insects are essential for the functioning of terrestrial ecosystems and play a critical role in ensuring food security; thus, studies on this topic provide significant benefits for human society. Pollination involves diverse taxa that can vary depending on the specific environment. Nevertheless, it is not always possible to monitor and study all pollinators of an ecosystem, as the research context is often constrained by financial and personnel limitations. European and national directives mostly focus on the monitoring of three taxa: bees (Hymenoptera: Apoidea: Anthophila), hoverflies (Diptera: Syrphidae) and lepidopterans (Lepidoptera). However, an effective prioritisation of taxa for pollinator research should consider their actual role as pollinators, which can vary according to the considered ecosystem. Moreover, knowledge about the specific potential of different taxa as pollinators in different ecosystems is still limited. Here, we evaluated, in mountain environments in the European Alps, the potential as pollinators of the three aforementioned taxa together with three other occurring flower-visiting taxa: beetles (Coleoptera), muscid flies (Diptera: Muscidae) and ants (Hymenoptera: Formicidae). We compared them in terms of flower visitor abundance and actual pollen transport. In addition, we evaluated whether the scientific efforts made thus far by European researchers aligned with the actual potential of the different taxa as pollinators in a mountain context. Bees and hoverflies have been found to be both the most effective pollen carriers and the most studied pollinators. Instead, a clear discrepancy is observed for muscid flies and lepidopterans, with the former being underrepresented in the scientific literature compared to their actual potential as pollinators, while the latter are overrepresented, ranking as the second most studied taxon despite being the least abundant visitors and contributing negligibly to pollen transport. Our purpose is not to generalise our findings, but to highlight the relevant discrepancies that may exist between the actual role of pollinators in specific ecosystems and the research efforts directed towards them.