How seed size, clutch size, and body size may constrain the evolution of life histories and resource use: An example with a seed beetle
Angela R. Amarillo-Suarez, email@example.com and Charles W. Fox, firstname.lastname@example.org. University of Kentucky, Department of Entomology, Lexington, KY
Intraspecific competition has important consequences for the fitness of organisms that develop on discrete resources. Larger animals may be more susceptible to food shortage and to increasing larval density in scramble competition systems. We measured the effect of clutch size and seed size on survivorship, development time and body size in two body size selected lines (Big and Small) and a control line of Stator limbatus. Females from each line were allowed to oviposit on one of three sizes of seeds and one of two host species. We used sets of lines with seven densities of eggs for each size-host combination. Body size was smaller and development time longer on the smallest seeds and at smaller clutch sizes. Survivorship decreased as clutch size increased and it was lower in all lines, at all clutch sizes, when organisms developed in the smallest host seed. Interactions between beetle body size and clutch/seed size were not all consistent. For example, larger animals did not experience a reduction in survival at high density when compared to small animals. These results show that body size and host size have important consequences for the evolution of life histories and resource use in organisms that, like S. limbatus, develop in discrete resources.
Species 1: Coleoptera Chrysomelidae Statorlimbatus (seed beetle) Species 2: Leguminosae Fabaceae Acaciagreggii (catclaw) Species 3: Leguminosae Fabaceae Pseudosamaneaguachapele (igua) Keywords: resource use, size