An integrative view of postcopulatory sexual selection in a soldier fly: Interplay between cryptic mate choice and sperm competition

Abstract

Cryptic female choice (CFC) can occur in the same species in conjunction with other postcopulatory processes, such as sperm competition (SC) and cryptic male choice (CMC). However, each of these processes has been mostly studied in isolation. Little is known about how they interact with each other and how this interplay affects the role they play in sexual selection. This chapter addresses the interplay between CFC, CMC, and SC in the soldier fly, Merosargus cingulatus (Diptera: Stratiomyidae). Soldier flies mate at oviposition sites; both sexes mate multiply and males perform copulatory courtship. Here, we describe the different postcopulatory processes that occur in this species: Females use control of oviposition timing as a CFC mechanism. Males show cryptic preferences for larger females and respond to SC cues by increasing copulation duration. Male reproductive success is, therefore, a result of a number of factors: Oviposition behavior, copulatory courtship, copulation duration, female size, and male density at the oviposition site. The interaction between CFC and other postcopulatory processes sheds light on its potential impact on sexual selection and evolution.