Abstract: Floral color and odor serve as attractants for pollinators. It remains unclear how changes in these traits in color-change species interact with pollinators and impact plants’ reproductive success. Lonicera calcarata flowers change from white (night 1 and day 1) through yellow (night 2) and orange (day 2) to orange-red (night 3 and day 3). Our research showed that floral characters, stigma activity, nectar production and floral spectral reflectance decreased through the flowering phases. Floral odor mainly comprised fatty acids, aldehydes, monoterpenes and alcohols, especially n-hexadecanoic acid, hexadecanal and 3-carene. Floral odor peaks on nights 1 and 3, largely due to presence of fatty acids. The emission of n-hexadecanoic acid was higher on nights 1 and 3 compared to other phases, while hexadecanal emission remained constant throughout the flowering stages. The emission of 3-carene was highest on night 1. L. calcarata was mainly pollinated by the moth Chorodna strixaria, the butterfly Acosmeryx naga and three bumblebees (Bombus melanurus, B. eximius, B. sonani) and they all preferred to visit white (younger) flowers. Moths had a preference for 3-carene and no significant preference for n-hexadecanoic acid and hexadecanal. Seed sets of nocturnal pollination and control treatments were not significantly different. L. calcarata could produce seeds by self-pollination, and cross-pollination significantly increased seed set. Floral color guides pollinators to visit younger flowers with more floral rewards and higher stigma activity. Different chemical compounds in floral odor may not only attract pollinators but also avoid herbivore damage.

Key words: Flower color, Flower scent, Lonicera calcarata, Plant strategy