Florivory and pollinator visitation: a cautionary tale

Abstract

Floral herbivory can make flowers less attractive to pollinators. To study the effect of floral herbivory on pollination in the hummingbird-pollinated sticky monkeyflower, we conducted field observations and experiments. We used two indicators of pollinator visitation: stigma closure and the presence of microorganisms in floral nectar. The field observations revealed that stigma closure was less frequent in damaged flowers than in intact flowers. In the experiments, however, floral damage did not decrease stigma closure or microbial detection. These results tell a cautionary tale: a negative association between florivory and pollinator visitation can be observed without florivory affecting pollinator visitation.

Genomic diversity of a nectar yeast clusters into metabolically, but not geographically, distinct lineages

“…We collected nectar from 12 M. aurantiacus plants per site and eight flowers per plant from 12 sites across an approximately 200‐km coastline around San Francisco, California (Figure c, Table , n = 1,152 flowers). We chose M. aurantiacus as the study species because this common native shrub pollinated primarily by hummingbirds ( Calypte anna ) produces a copious amount of nectar (up to 10 μl per flower) and because the knowledge gained through our previous field research with M. aurantiacus facilitated the design of this study (Belisle et al., ; Toju et al., ; Tsuji et al., ; Vannette & Fukami, ).…”

“…Table S1, n = 1,152 flowers). We chose M. aurantiacus as the study species because this common native shrub pollinated primarily by hummingbirds (Calypte anna) produces a copious amount of nectar (up to 10 ll per flower) and because the knowledge gained through our previous field research with M. aurantiacus facilitated the design of this study Toju et al, 2018;Tsuji et al, 2016;Vannette & Fukami, 2017).…”

Nectar yeasts: a natural microcosm for ecology

“…Furthermore, priority effects in flowers may also modify the pool of subsequent colonizers by affecting the foraging behaviour of pollinators. All of these processes can be studied through field experiments that are designed to establish causal relationships (Vannette & Fukami, ; Herrera et al, ; Schaeffer & Irwin, ; Toju et al, ; Tsuji et al, ).…”

Floral herbivory does not reduce pollination-mediated fitness in shelter rewarding Royal Irises

“…For example, Sõber et al (2010) experimentally showed a correlation between extent of florivory and pollinator visitations at both population and plant level. On the other hand, Tsuji et al (2016) found no evidence for pollinators discrimination against experimentally damaged flowers. Interestingly, mixed results can be found within the same system: Carper et al (2016) found differences between heterostylous morphs in pollinator responses to artificial damage, and found no effect on fitness.…”

“…In a survey of the literature, we found only a small number of studies that used controlled experimental florivory that mimics natural florivory by artificially manipulating or removing parts of the petals and tested for effect on pollination. Of these, seven studies found negative effect on pollination success, one study found mixed effects that depended on flower morph (Carper et al, 2016), and one study found no effect (Tsuji et al, 2016). Thus, it remains unclear whether florivory affects plant fitness indirectly via negative effects on pollinators.…”