Overcompensation for insect herbivory: a review and meta‐analysis of the evidence

Abstract

Not all herbivory is detrimental to plants. In some cases, plants can compensate for herbivory, maintain growth and fitness following damage, or even overcompensate for herbivory and perform better than if left undamaged. Examples of overcompensation to vertebrate herbivory are well known, but here we review the literature for examples of reproductive overcompensation (i.e., increased production of traits associated with fitness) and increased vegetative growth (i.e., vegetative overcompensation) following insect herbivory. We used a meta‐analysis to explore the effects of plant growth form, evolutionary history, herbivore feeding guild, and other plant and insect traits on the expression of reproductive and vegetative overcompensation by plants. Our literature search revealed 86 studies documenting examples of overcompensation for insect herbivory by 67 plant species representing 26 families. These plants included monocots and dicots, annuals and perennials, and woody and herbaceous plants. We also found that varied insect herbivores induce overcompensation, including 75 insect species in six orders representing 27 families and myriad feeding guilds. In our meta‐analysis, we calculated 53 effect sizes from 21 publications documenting reproductive overcompensation and 89 effect sizes from 40 publications documenting vegetative overcompensation. Variation in reproductive overcompensation was seen among plant growth forms, functional groups, cultivation, herbivore feeding sites, and plant and herbivore families. Variation in vegetative overcompensation was seen among plant families, herbivore families, and latitudinal gradients. We suggest overcompensation for insect herbivory may be far more prevalent than previously thought. Additional research focusing on the mechanisms, patterns, and ecological and evolutionary consequences of overcompensation for insect herbivory is likely to provide exciting new insights into this poorly understood and largely overlooked outcome of plant–insect interactions.

Overcompensation: a 30‐year perspective

“…The ecological context is known to affect the magnitude and even the direction of plant tolerance (Abrams , Chamberlain et al. , Garcia and Eubanks , Pearse et al. , Poveda et al.…”

“…The same seems plausible also for a wider range of crop plants. For example, a meta‐analysis of insect herbivory across plant growth forms by Garcia and Eubanks (, this Special Feature) demonstrates that many other cultivated plants show overcompensatory responses to damage that can be even greater than those of wild, uncultivated plants. As the next step, these findings all together highlight the need for applied research that aims to produce more concrete general guidelines for farmers on how to feasibly increase their yields.…”

“…Although a quantitative meta‐analysis provides a way to synthetize accumulated individual studies and to produce generalizations about plant tolerance to herbivory (Garcia and Eubanks , this Special Feature), we are still lacking broad, comparative studies that investigate plant defense strategies in relation to different abiotic and biotic factors and to different genetic and physiological potential and constraints. During the past 30 yr of tolerance and overcompensation studies, there has been a shift from describing patterns to exploring mechanisms, resulting in the rejection of some traditional hypotheses (e.g., a resistance–tolerance trade‐off).…”

“…The ecological context is known to affect the magnitude and even the direction of plant tolerance (Abrams 1987, Chamberlain et al 2014, Garcia and Eubanks 2019, Pearse et al 2017, Poveda et al 2018. As an example, the indirect positive effects of herbivores on plant performance are mediated by improved soil nutrient pools or by the removal of competitors (de Mazancourt et al 2001).…”

Lineage and latitudinal variation in Phragmites australis tolerance to herbivory: implications for invasion success

“…Herbivore‐induced growth is one example of adaptive phenotypic plasticity (Moreira et al ). Tolerance has also been shown to be genetically variable with genotypes within the same plant species ranging from under‐ to overcompensation (Tiffin and Rausher , Juenger and Bergelson , Siddappaji et al , Garcia and Eubanks ).…”