Jack‐of‐all‐trades paradigm meets long‐term data: Generalist herbivores are more widespread and locally less abundant

• Published in: Ecology letters Vol. 25; no. 4; pp. 948 - 957
• Main Authors: Sudta, Chanchanok, Salcido, Danielle M., Forister, Matthew L., Walla, Thomas R., Villamarín‐Cortez, Santiago, Dyer, Lee A., Novotny, Vojtech
• Format: Journal Article
• Language: English
• Published: England Blackwell Publishing Ltd 01.04.2022
• Subjects: abundance; Animals; Caterpillars; Diet; diet breadth; diet specialization; generalists; Herbivores; Herbivory; Hypotheses; Insecta; Insects; Lepidoptera; long‐term data; Occupancy; Plants; plant–herbivore interactions; Rare species; scaling; specialists; tropics; plant-herbivore interactions; scaling; diet specialization; tropics; abundance; long-term data; generalists; diet breadth; specialists
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/ele.13972

Insect herbivores are relatively specialized. Why this is so is not clear. We examine assumptions about associations between local abundance and dietary specialization using an 18‐year data set of caterpillar–plant interactions in Ecuador. Our data consist of caterpillar–plant associations and include standardized plot‐based samples and general collections of caterpillars, allowing for diet breadth and abundance estimates across spatial scales for 1917 morphospecies. We find that more specialized caterpillars are locally more abundant than generalists, consistent with a key component of the ‘jack of all trades, master of none’ hypothesis. As the diet breadth of species increased, generalists were not as abundant in any one location, but they had broader occupancy across the landscape, which is a pattern that could reflect high plant beta diversity and is consistent with an alternative neutral hypothesis. Our finding that more specialized species can be both rare and common highlights the ecological complexity of specialization. Using an 18‐year dataset of caterpillar‐plant interactions from Ecuador, we find that more specialized caterpillars are locally more abundant than generalists, consistent with a key component of the ‘jack of all trades, master of none’ hypothesis. As the diet breadth of species increased, those species were not as abundant in any one location, but they had greater occupancy across the landscape.