Sexual selection on cuticular hydrocarbons in the Australian field cricket, Teleogryllus oceanicus.
BACKGROUND
Females in a wide range of taxa have been shown to base their choice of mates on pheromone signals. However, little research has focussed specifically on the form and intensity of selection that mate choice imposes on the pheromone signal. Using multivariate selection analysis, we characterise directly the form and intensity of sexual selection acting on cuticular hydrocarbons, chemical compounds widely used in the selection of mates in insects. Using the Australian field cricket Teleogryllus oceanicus as a model organism, we use three measures of male attractiveness to estimate fitness; mating success, the duration of courtship required to elicit copulation, and subsequent spermatophore attachment duration.


RESULTS
We found that all three measures of male attractiveness generated sexual selection on male cuticular hydrocarbons, however there were differences in the form and intensity of selection among these three measures. Mating success was the only measure of attractiveness that imposed both univariate linear and quadratic selection on cuticular hydrocarbons. Although we found that all three attractiveness measures generated nonlinear selection, again only mating success was found to exert statistically significant stabilizing selection.


CONCLUSIONS
This study shows that sexual selection plays an important role in the evolution of male cuticular hydrocarbon signals.
Thomas
Melissa L
ML
Centre for Evolutionary Biology, School of Animal Biology, The University of Western Australia, Perth, Australia. mlthomas@cyllene.uwa.edu.au
Simmons
Leigh W
LW
D000818:Animals; D005075:Biological Evolution; D003307:Copulation; D005260:Female; D006135:Gryllidae / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D006838:Hydrocarbons / Q000737:chemistry*; D019476:Insect Proteins / Q000235:genetics; D008297:Male; D052586:Mating Preference, Animal; D015999:Multivariate Analysis; D025341:Principal Component Analysis; D019655:Quantitative Trait, Heritable; D012641:Selection, Genetic; D012724:Sex Attractants / Q000737:chemistry*
D006838:Hydrocarbons; D019476:Insect Proteins; D012724:Sex Attractants; C047663:cuticle proteins, insects