Post-copulatory sexual conflict and mate-guarding strategies in the Pacific field cricket (Teleogryllus oceanicus)

Abstract

This dissertation explores the role of post-copulatory song as a mate-guarding strategy in the Pacific field cricket, Teleogryllus oceanicus. In Chapter 1, I investigate how post-copulatory song influences female behavior and male fertilization success. I provide the first evidence of post-copulatory song in T. oceanicus and show that females exposed to this song are more likely to remain in close proximity to the male and retain the spermatophore, increasing the likelihood of fertilization with that male’s sperm. In Chapter 2, I examine the role of post-copulatory song in relation to the perceived risk of competition from other males. I find that the likelihood of using post-copulatory song is not influenced by exposure to acoustic cues of rival males. However, males perceiving less competition invest more in the song by decreasing latency to sing and increasing the time spent singing. In Chapter 3, I investigate potential physiological trade-offs between post-copulatory song and sperm viability; however, methodological limitations, particularly delayed sperm staining and buffer-induced degradation, prevent strong conclusions about a biological relationship between song and sperm viability. Overall, this dissertation reveals the role of post-copulatory song as a flexible mate-guarding tactic and highlights its influence on male reproductive success, responses to competition, and the trade-offs involved in reproductive strategy allocation.