Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1086/700577
Licence creative commons licence
Title (Primary) Delayed chemical defense: timely expulsion of herbivores can reduce competition with neighboring plants
Author Backmann, P.; Grimm, V.; Jetschke, G.; Lin, Y.; Vos, M.; Baldwin, I.T.; van Dam, N.M.
Source Titel American Naturalist
Year 2019
Department OESA; iDiv
Volume 193
Issue 1
Page From 125
Page To 139
Language englisch
Keywords induced defense, intraspecific competition, plant-herbivore interactions, trait diversity, individual-based model, simulation
Abstract Time delays in plant responses to insect herbivory are thought to be the principal disadvantage of induced over constitutive defenses, suggesting that there should be strong selection for rapid responses. However, observed time delays between the onset of herbivory and defense induction vary considerably among plants. We postulate that strong competition with conspecifics is an important codeterminant of the cost-benefit balance for induced responses. There may be a benefit to the plant to delay mounting a full defense response until the herbivore larvae are mobile enough to leave and large enough to cause severe damage to neighboring plants. Thus, delayed responses could reduce the competitive pressure on the focal plant. To explore this idea, we developed an individual-based model using data from wild tobacco, Nicotiana attenuata, and its specialized herbivore, Manduca sexta. Chemical defense was assumed to be costly in terms of reduced plant growth. We used a genetic algorithm with the plant’s delay time as a heritable trait. A stationary distribution of delay times emerged, which under high herbivore densities peaked at higher values, which were related to the time larvae need to grow large enough to severely damage neighboring plants. Plants may thus tip the competitive balance by expelling insect herbivores to move to adjacent plants when the herbivores are most damaging. Thus, herbivores become part of a plant’s strategy for reducing competition and increasing fitness.
Persistent UFZ Identifier
Backmann, P., Grimm, V., Jetschke, G., Lin, Y., Vos, M., Baldwin, I.T., van Dam, N.M. (2019):
Delayed chemical defense: timely expulsion of herbivores can reduce competition with neighboring plants
Am. Nat. 193 (1), 125 - 139 10.1086/700577