Signaling Vigor in Gryllodes Sigillatus: Relationship with Age and Foreign Body Ingestion

Abstract

Male Gryllidae acoustic signaling behaviour varies between and within species and may be influenced by a variety of factors including age, condition, and parasitism. I investigated variation within and among male Gryllodes sigillatus' mate attraction signaling behaviour and examined how variation in signaling vigour was influenced by age. I found extensive variation in male signaling between and within individuals; males differed in signaling vigour and quality, and their signaling changed over time. I found that smaller males signaled more consistently throughout their lives while larger males rarely called when younger and increased signaling vigour with age. As males have often been found to honestly signal their body condition (i.e., body mass), parasites may influence a male's perceived attractiveness to potential mates. I therefore also investigated how signaling vigour was influenced by the ingestion of the long barbed hastisetae from a typical pest species, dermestid (Dermestes ater), that plagues rearing facilities. These foreign bodies are regularly ingested during rearing. I found that males fed the highest concentration of dermestid hastisetae behaved differently than males in the control and high treatments. As individuals aged, smaller males greatly increased their signaling vigour and produced more attractive calls while larger males decreased their signaling vigour and produced less attractive calls. While further investigation into Gryllodes sigillatus signaling behaviour is needed, my results provide interesting insights into the factors shaping signaling variation in this species. Alyssa Froome Master of Science Fall 2022 iii Acknowledgements I am grateful to the Department of Biology at Carleton University for their assistance throughout my Master's education. I would like to personally thank Ed Bruggink and Dr. Genevieve Ferguson for helping with greenhouse maintenance and equipment repairs. I would also like to thank my committee members Drs. Gita Kolluru and Roslyn Dakin for providing invaluable feedback. I would like to extend a huge thank you to my supervisor Dr. Sue Bertram. She has provided me with unending guidance and support over the last five years and has pushed me to be a better researcher, scientist and student. The countless hours of meetings, editing and educating that she has invested over the course of my education is invaluable. She never lost faith even when every single bad thing that could happen did. Without her belief in me, guidance and support I would never have made it to where I am now. I would like to thank all members of the Bertram lab who have helped over the past few years. I would like to thank Mahir Awsaf, Emma McConnell and Olivia Gagnon who helped me immensely with cricket care, photographing and measuring. I would like to personally thank Matt Muzzatti for always being there to answer my questions, and for all his help on our joint dermestid research. Matt has taught me so much, especially (mostly against my will) about 'bugs'; I may never fully recover fr...