Modulation of sexual signalling by immune challenged male mealworm beetles (Tenebrio molitor, L.): evidence for terminal investment and dishonesty

Sadd, B.; Holman, L.; Armitage, H.; Lock, F.; Marland, R.; Siva-Jothy, M. T.

Abstract

Organisms partition resources into life‐history traits in order to maximise fitness over their expected lifespan. For the males of many species fitness is determined by qualitative and quantitative aspects of costly sexual signals: The notion that epigamic traits are costly forms the cornerstone of those theories that propose parasites drive sexual selection. Consequently studies examining this notion assume sexual signalling is honest (i.e. driven by cost) when they seek to identify correlations or causal links between male immune function and attractiveness. We demonstrate that immune challenged males of the mealworm beetle, Tenebrio molitor, increased their investment in epigamic pheromone signals: these males became significantly more attractive to females whilst increasing the activity of a key immune effector system. In other words males increase terminal reproductive effort (invest in attractiveness) in response to a survival threat (immune insult). Consequently the signal preferred by the female is dishonest when considering the male's condition.

Citation

Sadd, B., Holman, L., Armitage, H., Lock, F., Marland, R., & Siva-Jothy, M. T. (2006). Modulation of sexual signalling by immune challenged male mealworm beetles (Tenebrio molitor, L.): evidence for terminal investment and dishonesty. Journal of Evolutionary Biology, 19(2), 321-325. https://doi.org/10.1111/j.1420-9101.2005.01062.x

• Journal Article Type: Article
• Acceptance Date: Sep 6, 2005
• Online Publication Date: Jan 9, 2006
• Publication Date: 2006-03
• Deposit Date: Apr 14, 2021
• Journal: Journal of Evolutionary Biology
• Print ISSN: 1010-061X
• Electronic ISSN: 1420-9101
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 19
• Issue: 2
• Pages: 321-325
• DOI: https://doi.org/10.1111/j.1420-9101.2005.01062.x
• Keywords: dishonest signal, epigamic signal, immunity, pheromones, terminal investment, Tenebrio molitor
• Public URL: http://researchrepository.napier.ac.uk/Output/2761469