Evolutionary drivers of variation in sequestered defenses and warning coloration in a community of Milkweed bugs

• Applicant: Professor Dr. Georg Petschenka
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 558976240

It is largely unknown whether variation in antipredator defenses in aposematic prey is adaptive or reflects physiological constraints. Using a community of milkweed bugs that share the same host plant as a model system, we aim to unravel the evolutionary drivers underlying interspecific variation in sequestered chemical defenses and warning coloration. Specifically, we aim to test whether variation in sequestered cardenolides can be explained by (1) physiological mechanisms that reduce autotoxicity and minimize the cost of sequestration, or (2) the effectiveness of defenses in protecting against multiple natural predators. Addressing these questions will require the integration of biochemical and physiological assays, chemical analyses, image analysis and visual modeling, ecological fieldwork, and behavioral experiments with predators. This approach will provide new insights into the evolutionary plasticity of physiological mechanisms associated with toxin sequestration in herbivorous insects, and the role of variation in chemical and visual prey defenses in aposematism and mimicry.

• DFG Programme: Research Grants
• International Connection: Czech Republic
• Partner Organisation: Czech Science Foundation
• Cooperation Partner: Professorin Dr. Alice Exnerová