Tyler Wittman

Publication Date


Document Type


First Advisor

King, Bethia H.

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Chemical ecology; Insects--Behavior; Insects--Ecology


Use of chemical signals for sexual communication is found in a large proportion of insects. Pheromones may also act as honest signals of the sender's health and resources. Most research has focused on female-produced pheromones used for attracting mates over large distances or on the role pheromones play in species and mate recognition. Little work has been done exploring male produced pheromones, and how pheromones may be involved in mate assessment. Here I show that females of the parasitic wasp Urolepis rufipes discriminate for some aspects of male quality through the male's substrate-borne pheromones. In two-choice trials females spent more time near markings made by younger males, singly mated males which were not sperm-limited and uninfected males. The preference for uninfected males was only seen when testing males infected with an LD10 dose of bacteria against uninfected males; female preference disappeared when testing males infected with an LD50 dose against uninfected males. Our results are consistent with the terminal investment hypothesis, which posits that an organism's investment in current reproduction will be increased when faced with a loss of future reproductive potential. Thus males facing a high probability of death are predicted to invest more in current sexual signaling than males faced with a low probability of death. The low dose males may benefit from investment in immune function at the expense of sexual signaling due to the relatively high likelihood they have of overcoming the infection and reproducing in the future. The high dose males may benefit from forgoing investment in immune function in favor of current sexual signaling due to the high likelihood of death leading to a low likelihood of future reproductive success. In addition to preferring marks from young males, singly mated males and uninfected males, virgin females also preferred areas where multiple males had marked over areas where a single male had marked. However, marks per male were not greater with groups of males thus through his own attraction to male markings a male can better attract females with no apparent increase in the cost of attraction.


Advisors: Bethia H. King.||Committee members: Nich A. Barber; Rich B. King; Jon S. Miller.||Includes bibliographical references.


iii, 73 pages




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