Feeding damage to plants increases with plant size across 21 Brassicaceae species

Abstract

Plant size is a major predictor of ecological functioning. We tested the hypothesis that feeding damage to plants increases with plant size, as the conspicuousness of large plants makes resource finding and colonisation easier. Further, large plants can be attractive to herbivores, as they offer greater amounts and ranges of resources and niches, but direct evidence from experiments testing size effects on feeding damage and consequently on plant fitness is so far missing. We established a common garden experiment with a plant size gradient (10-130 cm height) using 21 annual Brassicaceae species, and quantified plant size, biomass and number of all aboveground components (flowers, fruits, leaves, stems) and their proportional feeding damage. Plant reproductive fitness was measured using seed number, 1000 seed weight and total seed weight. Feeding damage to the different plant components increased with plant size or component biomass, with mean damage levels being approximately 30 % for flowers, 5 % for fruits and 1 % for leaves and stems. Feeding damage affected plant reproductive fitness depending on feeding damage type, with flower damage having the strongest effect, shown by greatly reduced seed number, 1000 seed weight and total seed weight. Finally, we found an overall negative effect of plant size on 1000 seed weight, but not on seed number and total seed weight. In conclusion, being conspicuous and attractive to herbivores causes greater flower damage leading to higher fitness costs for large plants, which might be partly counterbalanced by benefits such as enhanced competitive/compensatory abilities or more mutualistic pollinator visits.

Plant size affects mutualistic and antagonistic interactions and reproductive success across 21 Brassicaceae species

“…; see also Schlinkert et al. , showing a correlation between plant size and feeding damage to flowers and fruits, but not to leaves and stems). Additionally, large plants may be highly attractive to associated insects by offering large microhabitat area and high quantity and variety of resources (Feeny , Lawton ).…”

“…; plant size, feeding damage to flowers, and reproductive success, but not flower herbivores and pollinators: Williams and Free , Sletvold and Grindeland , Schlinkert et al. , all studies but the last named focused on intraspecific plant size gradients). Besides, plant size moderated effects on mutualists and antagonists might further influence the ecological niches of co‐occurring plant species, their interspecific competition, the plants' overall fitness, and consequently long‐term evolutionary processes (Herrera and Pellmyr ).…”

How plant reproductive success is determined by the interplay of antagonists and mutualists

“…Larval development of pollen beetles can restrict flower and pod development (Lamb , Schlinkert et al. , b). Changes in landscape composition can alter the spatial distribution of pollen beetles and degree of local plant infestation (Gladbach et al.…”

The potential of crop management practices to reduce pollen beetle damage in oilseed rape

“…It seems, however, that no research has been carried out on the influence of these compounds on pest abundance or damage. As plant height can positively influence both pollen beetle and stem weevil Ceutorhynchus pallidactylus infestation (Schlinkert et al 2015(Schlinkert et al , 2016Ferguson et al 2003), it is possible that these compounds could be used to manipulate populations of these pests. Additionally, research is needed on the use of these or similar compounds to influence the timing of bud and flowering growth stages, as potential may exist to use growth regulators as an alternative to, or to enhance trap cropping strategies.…”