Attractive males have greater success in sperm competition

in male reproductive success, and thus amplifies pre-copulatory sexual selection [4]. In red flour beetles, for example, male precopulatory attractiveness is positively associated with success during sperm competition [5], and in guppies, more ornamented males sire more offspring when the sperm of two males are artificially inseminated in equal numbers [6]. Male mating advantage more generally has also been shown to correlate with fertilization success [7]. However, in water-striders, larger males have higher mating success, but smaller males secure a greater share of paternity from each mating [8]. As a result, preand post-copulatory sexual selection cancel each other out in this system and reduce the variance in male reproductive success [8]. Similarly, in Soay sheep, males that copulate most sire fewer offspring toward the end of the rut when they become sperm depleted and lose out in sperm competition [9]. Here, we investigate in the fly Drosophila simulans the relationship between female mate preference — a major component of pre-copulatory sexual selection — and fertilization success of the second of two males to copulate with a female (= P2). Female preference, which reflects male attractiveness, was measured as copulation latency: the speed with which a female mates with a male. Our design allowed us to investigate both phenotypic and genetic associations between these characters (Supplemental data). To assess phenotypic correlations we used multiple regression with the duration of copulation 1 and 2, number of offspring produced before copulation 2, number of offspring produced after copulation 2, female age at second copulation and copulation latency of the second male as our predictor variables. P2 (male fertilization success) was the dependent variable and data were transformed as appropriate (Supplemental data). Copulation latency was significantly negatively associated with P2 (F1,178 = 7.45; p = 0.007) — second males which took longer to copulate (less preferred males), sired fewer offspring (Figure 1). If males that monopolised paternity as second males were excluded, Attractive males have greater success in sperm competition