A systematic review of the direct and indirect effects of herbivory on plant reproduction mediated by pollination

Abstract

Background Plant reproduction is influenced by the net outcome of plant–herbivore and plant–pollinator interactions. While both herbivore impacts and pollinator impacts on plant reproduction have been widely studied, few studies examine them in concert. Methodology Here, we review the contemporary literature that examines the net outcomes of herbivory and pollination on plant reproduction and the impacts of herbivores on pollination through damage to shared host plants using systematic review tools. The direct or indirect effects of herbivores on floral tissue and reported mechanisms were compiled including the taxonomic breadth of herbivores, plants and pollinators. Results A total of 4,304 studies were examined producing 59 relevant studies for synthesis that reported both pollinator and herbivore measures. A total of 49% of studies examined the impact of direct damage to floral tissue through partial florivory while 36% of studies also examined the impact of vegetative damage on pollination through folivory, root herbivory, and stem damage. Only three studies examined the effects of both direct and indirect damage to pollination outcomes within the same study. Conclusions It is not unreasonable to assume that plants often sustain simultaneous forms of damage to different tissues and that the net effects can be assessed through differences in reproductive output. Further research that controls for other relative drivers of reproductive output but examines more than one pathway of damage simultaneously will inform our understanding of the mechanistic relevance of herbivore impacts on pollination and also highlight interactions between herbivores and pollinators through plants. It is clear that herbivory can impact plant fitness through pollination; however, the relative importance of direct and indirect damage to floral tissue on plant reproduction is still largely unknown.

Leaf Induction Impacts Behavior and Performance of a Pollinating Herbivore

“…In pollinatingherbivore species, adult fitness is affected by the presence of deterrent secondary compounds in nectar and larval fitness is affected by the defensive compounds in the tissues on which neonates hatch and feed. Floral volatiles may contain both attractive and repellant chemicals depending on the types of insects interacting with the plant, including pollinators, folivores, and/or florivores (Farré-Armengol et al, 2015;Rusman et al, 2019;Haas and Lortie, 2020). Whether adult pollinators use leaf and/or floral volatiles to determine foraging and oviposition choice is likely influenced by correlations between leaf and floral defense.…”

Pollinators and herbivores interactively shape selection on strawberry defence and attraction

“…Plant-herbivore interactions can likewise bear large consequences for pollination success (Kessleret al 2011;Muola et al 2017). The presence and action of herbivores, and in particular their damage to leaves (folivory) and flowers (florivory), can deter pollinators via a range of direct and indirect mechanisms (Jacobsen & Raguso 2018;Moreira et al2019;Haas & Lortie 2020). These include visually (e.g.…”

Pollinators and herbivores interactively shape selection on strawberry defence and attraction

“…Plant-herbivore interactions can likewise bear consequences for pollinator-mediated fitness (Kessler et al 2011;Muola et al 2017). The presence and action of herbivores, and in particular their damage to leaves (folivory) and flowers (florivory), can deter pollinators via a range of mechanisms (Jacobsen and Raguso 2018;Moreira et al 2019;Haas and Lortie 2020). Pollinator deterrence may be based on visual, olfactory, or gustatory cues, which can include altered floral aesthetics (McCall and Irwin 2006), release of herbivore-induced plant volatiles (Kessler and Chautá 2020), or the induction of unpalatable defensive compounds in floral nectar (Adler et al 2006).…”