Population ecology of an endemic and an invasive species

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The causes and consequences of population dynamics are the domain of population ecologists. Population dynamics of endemic and exotic species often differ in that outbreaks of endemic populations are temporary while those of exotic species are persistent. the most striking dynamics of endemic forest Lepidoptera in the northern hemisphere are population cycles. Characteristics associated with these population cycles are; a periodicity of 6 to 11 years between outbreaks, population increase over 5 to 8 years and then a rapid decline, no period of persistent low population density, and synchronicity among separate populations. For western tent caterpillars epizootics of a viral disease occur in population outbreaks. We propose to study two questions about tent caterpillar population dynamics: Is severity of viral infection in outbreak populations related to environmental conditions, and is the synchronicity of populations among sites environmentally determined or due to dispersal? We will use newly developed genetic markers to determine to what extent dispersal of moths among populations maintains synchronicity and field experiments and weather and population records to study viral epizootics.