Pollination success of highly specialised flowers is susceptible to fluctuations of thepollinator fauna. MediterraneanAristolochia rotundahas deceptive trap flowersexhibiting a highly specialised pollination system. The sole pollinators are kleptopara-sitic flies in search of food. This study investigates these pollinators on a spatio-tem-poral scale and the impact of weather conditions on their availability. Two potentialstrategies of the plants to cope with pollinator limitation,i.e.autonomous selfing andan increased floral life span, were tested.•A total of 6156 flowers were investigated for entrapped pollinators in 10 Croatianpopulations. Availability of the main pollinator was correlated to meteorological data.Artificial pollination experiments were conducted and the floral life span was recordedin two populations according to pollinator availability.•Trachysiphonella ruficeps(Chloropidae) was identified as dominant pollinator, alongwith less abundant species of Chloropidae, Ceratopogonidae and Milichiidae. Pollina-tor compositions varied among populations. Weather conditions 15–30 days beforepollination had a significant effect on availability of the main pollinator. Flowers werenot autonomously selfing, and the floral life span exhibited considerable plasticitydepending on pollinator availability.•A. rotundaflowers rely on insect pollen vectors. Plants are specialised on a guild ofkleptoparasitic flies, rather than on a single species. Pollinator variability may result indiffering selection pressures among populations. The availability/abundance of polli-nators depends on weather conditions during their larval development. Flowers showa prolonged trapping flower stage that likely increases outcrossing success during peri-ods of pollinator limitation.
Spatio-temporal patterns in pollination of deceptive aristolochia rotundal. (Aristolochiaceae)
Year: 2016
