Spatial and temporal dynamics of host-symbiont interactions in insects: Toward improving biological control programs against crop pests

Abstract

Symbionts are organisms living in association with other organisms, and are usually microorganisms transmitted either vertically to the next generation, or horizontally within and among species. They are providing several benefits for their hosts. After in important research effort, effects of symbionts on their hosts is still not fully understood, especially in terms of temporal and spatial population dynamics. A fascinating example concerns the pea aphid, Acyrthosiphon pisum (Hemiptera; Aphididae), that hosts a facultative symbiont, Hamiltonella defensa (Enterobacterales; Enterobacteriaceae) and - through the effect of a phage - the symbiont provides some level of protection against attacks of the parasitoid wasp, Aphidius ervi (Hymenoptera; Braconidae). Such an effect might jeopardize biological control programs of aphids through the release of parasitoid biological control agents. In this context, the scientific program proposed will be based on developing a modeling framework (mainly using Monte Carlo simulation coupled with genetic algorithms) to understand the temporal and spatial dynamics of the host-symbiont-parasitoid interactions. Several complementary models will be developed, and the results obtained will be used to optimize the efficacy of biological control programs against crop pests based on the release of parasitic wasps. Furthermore, effects of using a crop genetically modified for pest resistance on the overall output will also be analyzed using such a modeling framework. The expected results will be published in top-level international scientific journals. Finally, the proposed research activity will provide opportunities to teach in the research institution (Escola Superior de Agricultura Luiz de Queiroz (ESALQ) - Universidade de São Paulo (USP)), and to co-supervise Master and PhD students. (AU)