Applying geometric morphometrics to assess morphological divergence in bees

Applying geometric morphometrics to assess morphological divergence in beesJorge De La Cruz, Charles N. Thrift, Madeleine M. Ostwald, Katja C. Seltmann University of California Santa Barbara   Bees have relatively conserved wing morphology, but the divergence between groups remains poorly understood and has not been thoroughly quantified. Wing venation characteristics are fundamental for defining and classifying insects, but traditional methods of morphological identification for structures with complex geometries are challenging and time-consuming. This poses a challenge to the ease and accessibility of biodiversity research and studies examining ecological morphotypes. In this study, we employed geometric morphometrics to assess divergence in wing vein morphology across bee taxa. Geometric morphometrics allows for detailed shape analysis of wing structure, which may provide insights into evolutionary relationships. By digitally landmarking nine homologous wing vein characters of a large sample of bees, we quantified and compared morphological variation across several recognized species, genera, and families to assess whether the resulting morphological clusters reflect evolutionary divergence. Previous exploratory analyses demonstrate the ability to differentiate species within a genus and even among populations, testifying to a high level of precision. The extent to which our groupings based on morphometric data align with established phylogeny and the effects of allometry are investigated. This study assesses the potential of geometric morphometrics to infer the phylogenetic placement of indeterminate bee species based solely on wing vein morphology and practical implications for an efficient species identification pathway.This presentation was presented at the UCSB EEMB Undergraduate Research Symposium - 2025