title: Herbivory Increases Fruit Set in Silene latifolia: A Consequence of Induced Pollinator-Attracting Floral Volatiles?
abstract: Although the effect of herbivory on plant reproduction has been investigated in some detail, little is known about how herbivores affect floral signalling. Here, we investigated the effect of foliar herbivory by the African Cotton Leafworm (Spodoptera littoralis) on floral signalling and fruit set in the White Campion (Silene latifolia). We found no effects of herbivory on floral traits involved in visual signalling (flower number, corolla diameter, calyx length, petal length) or in amount of nectar produced. However, Spodoptera-infested plants emitted higher amounts of the two floral volatiles, (Z)-3-hexenyl acetate and β-ocimene, than control plants. Open pollinated, infested plants also were found to produce more fruits than control plants, but only with nocturnal pollinators. Experimental addition of the two induced floral volatiles to non-infested Silene flowers also led to the production of more fruits with nocturnal pollination. This suggests that higher fruit production in herbivore-infested plants was caused by increased nocturnal pollinator attraction, mediated by the induced floral emission of these two volatiles. Our results show that the effects of herbivory on plant reproductive success are not necessarily detrimental, as plants can compensate herbivory with increased investment in pollinator attraction.
authors.affiliation: Consiglio Nazionale delle Ricerche, Institute for Sustainable Plant Protection, Via Madonna del Piano, 10, I-50019, Sesto Fiorentino, FI, Italy, cozzolin@unina.it.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cozzolino
authors.forename: Silvia
authors.initials: S
authors.lastname: Fineschi
authors.forename: Maria
authors.initials: M
authors.lastname: Litto
authors.forename: Giovanni
authors.initials: G
authors.lastname: Scopece
authors.forename: Judith
authors.initials: J
authors.lastname: Trunschke
authors.forename: Florian P
authors.initials: FP
authors.lastname: Schiestl
mesh_terms: D000085:Acetates / Q000378:metabolism; D000080462:Acyclic Monoterpenes; D000475:Alkenes / Q000378:metabolism; D000818:Animals; D035264:Flowers / Q000502:physiology*; D005638:Fruit / Q000502:physiology*; D060434:Herbivory; D054817:Pollination; D029751:Silene / Q000502:physiology*; D018411:Spodoptera / Q000502:physiology*; D055549:Volatile Organic Compounds / Q000378:metabolism
chemical_list: D000085:Acetates; D000080462:Acyclic Monoterpenes; D000475:Alkenes; D055549:Volatile Organic Compounds; C443996:beta-ocimene; C425828:3-hexenylacetate