Nectar replenishment maintains the neutral effects of nectar robbing on female reproductive success of Salvia przewalskii (Lamiaceae), a plant pollinated and robbed by bumble bees

Abstract

Nectar robbing did not affect female reproductive success because nectar replenishment ensures that pollinators maintain their visiting activity to nectar-robbed flowers. Nectar replenishment might be a defence mechanism against nectar robbing to enhance reproductive fitness by maintaining attractiveness to pollinators. Further studies are needed to reveal the potential for interference competition among bumble bees foraging as robbers and legitimate visitors, and to investigate variation of nectar robbing in communities with different bumble bee species composition.

Variation in composition of two bumble bee species across communities affects nectar robbing but maintains pollinator visitation rate to an alpine plant, Salvia przewalskii

“…Nectar replenishment of the plant is fast and plentiful and, moreover, does not differ between robbed and legitimate flowers (Ye et al, 2017). In the studied area, the plant is exclusively pollinated as well as robbed by bumble bees.…”

“…var. Most flowers last for 2.5 days before they begin to wilt (Ye et al, 2017). It inhabits hillsides, subalpine meadows, forest margins, roadsides, and thickets, with the flowering season usually running from August to September.…”

“…In the studied area, the plant is exclusively pollinated as well as robbed by bumble bees. Nectar replenishment has been ascribed to the neutral effects of nectar robbing on female reproductive success by maintaining attractiveness to pollinators (Ye et al, 2017). In addition, behaviours of legitimate visitors as well as female reproductive success of S. przewalskii are not significantly affected by level of nectar robbing (Ye et al, 2017).…”

“…Nectar replenishment of the plant is fast and plentiful and, moreover, does not differ between robbed and legitimate flowers (Ye et al, 2017). However, the effects of community context on interactions among bumble bees foraging as robbers and legitimate visitors, and thus accounting for variation in nectar robbing and pollination in S. przewalskii from different communities, still require investigation (Ye et al, 2017). Nectar replenishment has been ascribed to the neutral effects of nectar robbing on female reproductive success by maintaining attractiveness to pollinators (Ye et al, 2017).…”

Time-Dependent Trapping of Pollinators Driven by the Alignment of Floral Phenology with Insect Circadian Rhythms

“…Although Annonaceae species are typically dependent on a single guild of pollinators (Saunders, 2012), the pollinators are not reciprocally dependent since they obtain nutrition from many different sources; the circadian traps are therefore likely to have resulted from evolutionary changes in plant phenology rather than changes in beetle circadian rhythms, and are not the result of co-evolution. The timing of anthesis and floral-reward production within each day are likely shaped by the activity peaks of pollinators in order to maximize pollination efficiency (Stebbins, 1970; Armbruster and McCormick, 1990; Herrera, 1990; Jagadish et al, 2002; Kulloli et al, 2011; Prieto-Benítez et al, 2016). Significantly, however, studies of the relationship between the circadian rhythms of pollinators and floral phenology are generally lacking: although previous assessments of pollinator activity have relied on monitoring of floral visits, it has been suggested that in order to study the evolution of floral changes in response to pollinator activity it is more appropriate to assess pollinator activities independently of their interaction with flowers (Armbruster and McCormick, 1990).…”