Prey nutrient content creates omnivores out of predators
| Autor: | Robert J. Grebenok, Todd A. Ugine, John E. Losey, Stuart B. Krasnoff, Spencer T. Behmer |
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| Rok vydání: | 2018 |
| Předmět: |
0106 biological sciences
Herbivore Food Chain Ecology Applied ecology Nutrients Biology biology.organism_classification 010603 evolutionary biology 01 natural sciences Coccinella septempunctata Diet Nutrient content Predation Coleoptera 010602 entomology Nutrient Predatory Behavior Animals Herbivory Omnivore Ecology Evolution Behavior and Systematics Trophic level |
| Zdroj: | Ecology Letters. |
| ISSN: | 1461-0248 1461-023X |
| Popis: | The proximate forces that create omnivores out of herbivores and predators have long fascinated ecologists, but the causal reasons for a shift to omnivory are poorly understood. Determining what factors influence changes in trophic position are essential as omnivory plays a central role in theoretical and applied ecology. We used sevenspotted lady beetles (Coccinella septempunctata) to test how prey nutrient content affects beetles' propensity to engage in herbivory. We show that beetles consuming an all-prey diet demonstrate normal growth and development, but suffer a complete loss of fitness (spermatogenic failure) that is restored via herbivory and supplementation with phytosterols and cholesterol. Furthermore, we show that lady beetles possess a state-dependent sterol-specific appetite and redressed their sterol deficit by feeding on foliage. These results demonstrate that predators balance their nutrient intake via herbivory when prey quality is low, and reveal a selective force (sterol nutrition) that drives predatory taxa to omnivory. |
| Databáze: | OpenAIRE |
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