Meeting Abstract
Mandibles are critical to the biology of ants, being the primary structures they use to interact with their environment. To explain why ants are so evolutionarily successful, it is critical to understand the relationship between mandible morphology and their ecological and mechanical performance. In this study, we examined the form and function of mandibles in fungus-growing ants, who display a great deal of mouthpart morphological diversity and variation in the fungus they cultivate. Using light microscopy and geometric morphometrics, we quantified head and mandible morphology for 70 species of fungus-growing ants in 13 genera. Additionally, we used X-ray microtomography to visualize mandible muscle morphology and lever geometry to indirectly estimate mandible performance. Our preliminary results indicate significant differences in head shape between agricultural systems of fungus-growing ants. Specifically, species with higher and leaf-cutting agricultural systems were found to have wider and longer heads, particularly along the posterior margin, compared with ants with lower and yeast agricultural systems. Coral fungus ants, represented by the genus Apterostigma, had heads that were significantly narrower than the other two morphological groups. These differences in head shape may reflect the mechanical requirements for processing different fungal substrates. Combined with a well-resolved phylogeny, these data can provide insight into the complex interactions between morphology, ecological performance, and patterns of biodiversity.
