Relative Role of Flower Color and Scent on Pollinator Attraction: Experimental Tests using F1 and F2 Hybrids of Daylily and Nightlily

Abstract

The daylily (Hemerocallis fulva) and nightlily (H. citrina) are typical examples of a butterfly-pollination system and a hawkmoth-pollination system, respectively. H. fulva has diurnal, reddish or orange-colored flowers and is mainly pollinated by diurnal swallowtail butterflies. H. citrina has nocturnal, yellowish flowers with a sweet fragrance and is pollinated by nocturnal hawkmoths. We evaluated the relative roles of flower color and scent on the evolutionary shift from a diurnally flowering ancestor to H. citrina. We conducted a series of experiments that mimic situations in which mutants differing in either flower color, floral scent or both appeared in a diurnally flowering population. An experimental array of 6×6 potted plants, mixed with 24 plants of H. fulva and 12 plants of either F1 or F2 hybrids, were placed in the field, and visitations of swallowtail butterflies and nocturnal hawkmoths were recorded with camcorders. Swallowtail butterflies preferentially visited reddish or orange-colored flowers and hawkmoths preferentially visited yellowish flowers. Neither swallowtail butterflies nor nocturnal hawkmoths showed significant preferences for overall scent emission. Our results suggest that mutations in flower color would be more relevant to the adaptive shift from a diurnally flowering ancestor to H. citrina than that in floral scent.

Plant scents modify innate colour preference in foraging swallowtail butterflies

“…In the wild, P. xuthus often feed on reddish flowers [14]. Females might initially feed successfully from reddish flowers thanks to their innate preference being modified by floral scent.…”

Understanding the Complex Structure of a Plant-Floral Visitor Network from Different Perspectives in Coastal Veracruz, Mexico

“…pollinators (Richards, 1997), and have provided some of the strongest support for pollinator driven floral evolution (Danieli-Silva et al, 2012;Hirota et al, 2012). However, they could be misused, such that without previous observations a person could judge or ascertain which type of pollinator visits a certain plant species.…”

A new family placement for Australian blue squill, Chamaescilla: Xanthorrhoeaceae (Hemerocallidoideae), not Asparagaceae

“…These features are found in most of the johnsonioid and phormioid genera, except for Phormium, which has large tubular flowers for bird pollination (Furness et al 2014). In the hemerocallid clade, Hemerocallis has large pollen and slightly zygomorphic flower symmetry for pollination by butterflies or hawkmoths (Hirota et al 2012), while Simethis retains the buzz pollination features found in the rest of the family. Chamaescilla lacks hairy filaments and has large pollen indicating that buzz pollination may have been lost, but blue flower colour is considered to be a feature of bee pollination (Kevan 1983).…”