Research Projects

Competition is a driving force of ecological diversity, where individuals or groups share limited resources. When two species compete for the same niche, they may reduce competition through niche partitioning, leading to specialization. Ecological theory suggests that interspecific competition can cause ecological specialization, but experimental and comparative studies suggest it favors generalization. The host-parasite system is ideal for studying this effect, as the host as a limiting resource is well defined and tractable. Parasitoids, which lay their eggs in/on the host body, have a close relationship with their host and their ability to use a host depends on host size, stage, immunity, and accessibility. Host finding efficiency is a major competitive factor between two parasitoid species with a shared host or niche. Generalist species with a wide host species range will face more competitive pressure than specialist species with a narrow range. Specialist species have evolved adaptations for finding and exploiting hosts more efficiently than generalist species. The hypothesis proposed is that interspecific competition between generalist parasitoids on two hosts will pressurize the less competitive parasitoid species to end up with the less preferred host, eventually evolving specialization with generation over that host species. This hypothesis will be tested using a laboratory selection experiment, which will analyze changes in host preference and performance with generations. This study can contribute to integrated pest management, as specialist species are a more proficient natural enemy than generalists.