Sperm competition in Callosobruchus maculatus (Coleoptera: Bruchidae): a comparison of two methods used to estimate paternity

Abstract.

• 1 This study investigates sperm competition in Cullosobruchus maculatus (F.) (Coleoptera: Bruchidae), and is the first study to make a direct, controlled comparison of the sterile male and genetic marker techniques to estimate sperm precedence.
• 2 P₂ values (the proportion of offspring fathered by the second male) obtained from the two methods were similar: P₂ (sterile male) = 0.82, P₂ (genetic marker) = 0.85. Both methods are therefore suitable for studying sperm precedence if the appropriate correction factors are applied.
• 3 The importance of general fertilization ability, differential fertilizing capacity and differential zygote mortality are examined and discussed.