The hidden diptera diversity in aristolochia trap-flowers: revealing the identity of pollinators through taxonomic knowledge

Abstract

Although Diptera is one of the most diverse insect orders with a high potential for pollinating plants, it remains poorlystudied and neglected. This is partly due to limited taxonomic efforts in species identification. For instance, despite beingprimary pollinators of trap flowers, species-level identification in these systems remains scarce. To highlight this taxonomicimpediment, we reviewed the diversity of Diptera pollinators found on trap flowers of Aristolochia (Aristolochiaceae), agenus exclusively pollinated by flies. We recorded the number of morphospecies identified at the order, family, genus, andspecies levels across Aristolochia populations and calculated the percentage of species-level identification for each popula-tion. To propose a solution to the taxonomic impediment, we used data from an Aristolochia esperanzae population, compar-ing the taxonomic refinement without and with taxonomist collaboration. Our review yielded 531 Diptera records from 40populations across 23 Aristolochia species. Of these, 1.9% were identified at the order, 41% at the family, 35.8% at the genus,and only 21.3% at the species levels. The mean percentage of species-level identification for the populations was 34.11%,with 40% of populations showing < 5% of species identified. Overall, 43 families, 109 genera, and 61 species of Diptera wererecorded as potential pollinators of Aristolochia. Our case study demonstrated that collaboration with taxonomists improvedtaxonomic refinement, particularly at the genus and species levels, with this latter rising from 0% to 38.8%. This collabora-tion also enabled the identification of main pollinators of A. esperanzae, which belong to Ulidiidae, a little-known pollinator family. This study highlights a substantial taxonomic impediment in Diptera pollinators of Aristolochia, which may limitour understanding of their role in plant pollination. Additionally, we demonstrate the importance of interdisciplinary col-laboration with insect taxonomists to improve our comprehension of biological and ecological patterns involving the highlydiverse yet less-known dipteran pollinators.