Chemical Ecology of Mate Choice
Developing a comprehensive understanding of the relative roles that functionally dissimilar traits play in the evolutionary ecology of Müllerian mimicry complexes is a central goal of the Heliconius butterfly research program. Wing coloration and pattern have long been implicated as key traits driving assortative mate choice within and between phenotypically distinct populations, races, and species of Heliconius. However, the relative role that volatile pheromone chemistry plays in Heliconius mate choice has received considerably less attention.
Heliconius erato petiverana: Left - male being prepared for experiment by painting nail varnish over andronial cells
Center - experimental male with colored cells obstructed (right) mating with virgin female (left)
Right - control male with nail varnish painted on dorsal hind wing, androconial cells unobstructed (top), with virgin female (bottom)
Center - experimental male with colored cells obstructed (right) mating with virgin female (left)
Right - control male with nail varnish painted on dorsal hind wing, androconial cells unobstructed (top), with virgin female (bottom)
Given the ubiquitous nature of semiochemical communication in nature, and strong evidence of the importance of chemistry influencing mate choice from investigations of other lepidopteran taxa, the effect of pheromone chemistry in mate choice of Heliconius butterflies is beginning to receive greater appreciation.
My collaegues and I have explored the significance of pheromone chemistry in several Heliconius taxa through series of manipulative behavioral experiments, and analytical chemistry. Male pheromones affect female mate choice, as demonstrated through rounds of choice tests in which male pheromone emission was obstructed. Moreover, obstruction of wing color corroborates results of these experiments generating new questions on the dimensions of color pattern and chemistry as cues for mate preference. Disparate chemical profiles amongst geographically distinct Heliconius taxa suggest that there may be selection for chemical variation following assortative mating.
My collaegues and I have explored the significance of pheromone chemistry in several Heliconius taxa through series of manipulative behavioral experiments, and analytical chemistry. Male pheromones affect female mate choice, as demonstrated through rounds of choice tests in which male pheromone emission was obstructed. Moreover, obstruction of wing color corroborates results of these experiments generating new questions on the dimensions of color pattern and chemistry as cues for mate preference. Disparate chemical profiles amongst geographically distinct Heliconius taxa suggest that there may be selection for chemical variation following assortative mating.