Understanding the functional and evolutionary significance of morphology is key to interpreting the tree of life. Recent tools enable broad-scale analysis of morphological data and entire phenomes, helping re-establish morphology as central to evolutionary biology. This is especially critical for hyperdiverse groups like Ichneumonidae, the most species-rich family of parasitoid wasps, which show repeated morphological convergence, complex life histories, and diverse host associations. To study phenome evolution effectively, characters must be clearly defined, terminology standardized through ontologies, and a robust, time-calibrated phylogeny must be available. While progress has been made, these foundational components remain limited for Ichneumonidae. My dissertation addresses these gaps to advance our understanding of morphology and its role in parasitoid wasp evolution. I integrate diverse anatomical systems and approaches across four chapters. I develop a standardized terminology for male genitalia in Ichneumonoidea by aligning legacy terms with the Hymenoptera Anatomy Ontology (Chapter 2). I describe a novel steering mechanism of the ovipositor, including a sclerite functionally similar to the furcula in Aculeata (Chapter 3). I investigate convergent morphological syndromes in parasitoids of wood-boring hosts, revealing repeated evolution of functionally similar traits (Chapter 4). I assess evolutionary rate variation across a time-calibrated phylogeny to test whether major transitions in host use correlate with shifts in the tempo of morphological evolution (Chapter 5). This work uncovers novel traits, establishes tools for morphological research, and host use to evolutionary rate shifts. Collectively, it lays the groundwork for broad-scale phenomic studies in parasitoid wasps and highlights morphology’s central role in understanding evolutionary processes.
Davide Dal Pos
Dr. Barbara J. Sharanowski, Advisor
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