title: Resource quality affects weapon and testis size and the ability of these traits to respond to selection in the leaf-footed cactus bug, Narnia femorata.
abstract: The size of weapons and testes can be central to male reproductive success. Yet, the expression of these traits is often extremely variable. Studies are needed that take a more complete organism perspective, investigating the sources of variation in both traits simultaneously and using developmental conditions that mimic those in nature. In this study, we investigated the components of variation in weapon and testis sizes using the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae) on three natural developmental diets. We show that the developmental diet has profound effects on both weapon and testis expression and scaling. Intriguingly, males in the medium-quality diet express large weapons but have relatively tiny testes, suggesting complex allocation decisions. We also find that heritability, evolvability, and additive genetic variation are highest in the high-quality diet for testis and body mass. This result suggests that these traits may have an enhanced ability to respond to selection during a small window of time each year when this diet is available. Taken together, these results illustrate that normal, seasonal fluctuations in the nutritional environment may play a large role in the expression of sexually selected traits and the ability of these traits to respond to selection.
authors.affiliation: Whitney Laboratory for Marine Bioscience University of Florida 9505 Ocean Shore Blvd St. Augustine Florida 32080.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Sasson
authors.affiliation: Department of Agronomy University of Florida 2005 SW 23 St. Bldg 350 Gainesville Florida 32611.
authors.forename: Patricio R
authors.initials: PR
authors.lastname: Munoz
authors.affiliation: School of Forest Resources & Conservation University of Florida PO Box 110410 Gainesville Florida 32611.
authors.forename: Salvador A
authors.initials: SA
authors.lastname: Gezan
authors.affiliation: Entomology and Nematology Department University of Florida PO Box 110620 Gainesville Florida 32611.
authors.forename: Christine W
authors.initials: CW
authors.lastname: Miller
keywords: Development; Narnia femorata; evolvability; heritability; nutrition; sexual selection; testes; weapons