Niche evolution speeds invasion by the cinnabar moth: the role of climate, hosts, and enemies

Range expansion by an invader depends on the boundaries of the multidimensional and evolving niche.  The niche can be operationalized as the range of environments (including abiotic and biotic factors) within which the population growth rate is positive.  We estimated niche boundaries by experimentally rearing families and populations of the cinnabar moth (Tyria jacobaeae) throughout the life cycle over a range of temperatures (15, 20, 25 ^o C), host species (both ancestral and acquired host species), and pathogen (Nosema tyriae) intensities; we then projected population growth rates using a matrix model.  We found that abiotic and biotic factors interact to promote range expansion as this insect invades high elevation environments.  We conclude that adaptation to climate can promote the acquisition of new hosts, reduce disease risk, and speed the overall rate of invasion.