Abstract

Effects of the social environment on reproductive behavior are widespread. How the social environment promotes or inhibits behavioral plasticity is less known. I examined the role of male harassment and larval competition on reproductive behaviors in Callosobruchus maculatus. For experiment one, I manipulated male harassment level during female oviposition. I measured oviposition substrate preference, clutch size, egg size, and the trade-off between egg and clutch size. For experiment two, I investigated the effect of the social environment during larval development inside the bean. Groups consisted of a control and sex-ratio-based competition treatments. I recorded the mating behavior of all emerged individuals and the clutch sizes of emerged females. My results demonstrated that male harassment, but not larval competition, impacted reproductive behavior. Specifically, male harassment decreased reproductive plasticity. The trade-off between egg and clutch size disappeared, clutch size decreased, and adaptive oviposition preferences were lost. Reproductive plasticity appears to be context-dependent.

Keywords: Callosobruchus maculatus, bean beetle, seed beetle, male harassment, larval competition, sperm competition, egg and clutch size trade-off, oviposition, social environment, behavioral plasticity, sex ratio.

Related Links:

• The Impact of the Social Environment on Reproductive Plasticity: The Role of Male Harassment and Larval Competition in Callosobruchus maculatus.pdf (PDF)