Butterfly pollination and high-contrast visual signals in a low-density distylous plant.
In low-density butterfly-pollinated Mussaenda frondosa (Rubiaceae), flowers attract pollinators at short distances while conspicuous, non-rewarding accessory bracts are detectable at long distances by long-ranging pollinators such as the birdwing butterfly Troides minos that did not detect flower-bearing plants in the absence of these bracts. However, even in the absence of flowers, the white, ultraviolet-absorbing bracts attracted butterflies that visited flowerless plants. Although flower visits by short-ranging territorial butterflies declined significantly on removal of bracts, they did not cease completely. Nectar-robbing carpenter bees and birds did not change their behaviour following bract removal. Bract removal caused a significant decline in fruit set, indicating their importance as visual signals to pollinators.
Borges
Renee M
RM
Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 012, India. renee@ces.iisc.ernet.in
Gowda
Vinita
V
Zacharias
Merry
M
D000818:Animals; D001516:Bees; D001717:Birds; D002080:Butterflies; D035264:Flowers; D009068:Movement; D012098:Reproduction; D019666:Rubiaceae / Q000502:physiology*; D014466:Ultraviolet Rays; D014796:Visual Perception