Estimating pollination success with novel artificial flowers: Effects of nectar concentration

Abstract

We developed novel artificial flowers that dispense and receive powdered food dyes as pollen analogues while their nectar is replenished by capillary action. Dye receipt, which can be measured colourimetrically, is a direct surrogate for pollen receipt or female reproductive success, but can also serve to compare pollen donation (male reproductive success) from flowers with different colours of dye. By allowing captive bumble bee colonies to visit large arrays of such flowers, we investigated whether total dye receipt depended on the sugar concentration of a flower’s nectar. Estimating pollen transfer, rather than simply visitation rate, is appropriate for this question because flowers with more concentrated nectar might accrue more pollen not only through higher visitation rates but also through longer visits that transfer more pollen per visit. Flowers with richer nectar did receive more dye regardless of their spatial arrangement, but the effect was greatest when rich and poor flowers were segregated in large blocks, as opposed to being intermingled.

An analysis of the energetic reward offered by field bean (Vicia faba) flowers: Nectar, pollen, and operative force

“…In combination with the findings of Thomson et al. (), the results of this study suggest that breeding for nectar sugar concentrations up to 55% w/w nectar will improve pollinator preference and pollen transfer. However, breeding beyond this concentration would have no further beneficial effects and not only waste plant resources but also increase the amount of time it takes for a bee to visit a flower (Harder, ).…”

“…Our findings improve on previous work investigating bee preference for high sugar concentrations (e.g., Mommaerts, Wäckers, & Smagghe, 2013; Waller, 1972;Woodrow, 1968) using realistic volumes of reward within a flower under free flight conditions with a single forager present so that choices are not influenced by social cues. In combination with the findings of Thomson et al (2012), the results of this study suggest that breeding for nectar sugar concentrations up to 55% w/w nectar will improve pollinator preference and pollen transfer. However, breeding beyond this concentration would have no further beneficial effects and not only waste plant resources but also increase the amount of time it takes for a bee to visit a flower (Harder, 1986).…”

“…Recently, it has been shown that more pollen analog is transferred to artificial flowers with a higher sugar concentration when bees are allowed to choose freely between two different concentrations (Thomson et al, 2012). This suggests that improving the sugar concentration of flowers will be a successful strategy to improve pollination rates in V. faba.…”

Impact of single visit of Chalicodoma cincta Fabricius 1871 (Hymenoptera: Megachilidae) on Ceratotheca sesamoides Endl. 1753 (Pedaliaceae) flowers at Ngaoundéré (Cameroon)

“…The attractiveness of Ce. sesamoides nectar could be partially explained by its reported high production and total sugar concentration (27.76 -30.60%) [7], compared to range 15-75% in which most of the plant species fall [25] . The abundance of Ch.…”

Flobots: Robotic flowers for bee behaviour experiments

“…1). A particularly inexpensive and versatile design is described by Makino and Sakai (2007) and further developed by Thomson et al (2012). In these flowers, a thin wick carries sugar solution from a reservoir into a flower.…”