title: Is bigger better? Male body size affects wing-borne courtship signals and mating success in the olive fruit fly, Bactrocera oleae (Diptera: Tephritidae).
abstract: Variations in male body size are known to affect inter- and intrasexual selection outcomes in a wide range of animals. In mating systems involving sexual signaling before mating, body size often acts as a key factor affecting signal strength and mate choice. We evaluated the effect of male size on courtship displays and mating success of the olive fruit fly, Bactrocera oleae (Diptera: Tephritidae). Wing vibrations performed during successful and unsuccessful courtships by large and small males were recorded by high-speed videos and analyzed through frame-by-frame analysis. Mating success of large and small males was investigated. The effect of male-male competition on mating success was evaluated. Male body size affected both male courtship signals and mating outcomes. Successful males showed wing-borne signals with high frequencies and short interpulse intervals. Wing vibrations displayed by successful large males during copulation attempt had higher frequencies over smaller males and unsuccessful large males. In no-competition conditions, large males achieved higher mating success with respect to smaller ones. Allowing large and small males to compete for a female, large males achieve more mating success over smaller ones. Mate choice by females may be based on selection of the larger males, able to produce high-frequency wing vibrations. Such traits may be indicative of "good genes," which under sexual selection could means good social-interaction genes, or a good competitive manipulator of conspecifics.
authors.affiliation: Insect Behaviour Group, Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benelli
authors.affiliation: The BioRobotics Institute, Sant'Anna School of Advanced Studies, Pontedera, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Donati
authors.affiliation: Insect Behaviour Group, Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy.
authors.forename: Donato
authors.initials: D
authors.lastname: Romano
authors.affiliation: The BioRobotics Institute, Sant'Anna School of Advanced Studies, Pontedera, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Ragni
authors.affiliation: The BioRobotics Institute, Sant'Anna School of Advanced Studies, Pontedera, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Bonsignori
authors.affiliation: The BioRobotics Institute, Sant'Anna School of Advanced Studies, Pontedera, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Stefanini
authors.affiliation: Insect Behaviour Group, Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Canale
mesh_terms: D000818:Animals; D049628:Body Size; D003163:Competitive Behavior; D003380:Courtship; D005260:Female; D008297:Male; D012726:Sexual Behavior, Animal; D033621:Tephritidae / Q000502:physiology*; D014921:Wings, Animal / Q000502:physiology
keywords: communication channels; courtship call; male-male competition; mate choice; sexual selection; social resources