Life Sciences Commons^™

Climate-Related Geographical Variation In Performance Traits Across The Invasion Front Of A Widespread Non-Native Insect, Lily M. Thompson, Sean D. Powers, Ashley Appolon, Petra Hafker, Leila Milner, Dylan Parry, Salvatore J. Agosta, Kristine L. Grayson

Biology Faculty Publications

Aim

Invasive species are ideal systems for testing geographical differences in performance traits and measuring evolutionary responses as a species spreads across divergent climates and habitats. The European gypsy moth, Lymantria dispar dispar L. (Lepidoptera: Erebidae), is a generalist forest defoliator introduced to Medford, Massachusetts, USA in 1869. The invasion front extends from Minnesota to North Carolina and the ability of this species to adapt to local climate may contribute to its continuing spread. We evaluated the performance of populations along the climatic gradient of the invasion front to test for a relationship between climate and ecologically important performance traits. …

Spatiotemporal Variability In Allee Effects Of Invading Gypsy Moth Populations, Jonathan A. Walter, Kristine L. Grayson, Laura M. Blackburn, Patrick C. Tobin, Derek M. Johnson

Biology Faculty Publications

The Allee threshold, the critical population density separating growth from decline in populations experiencing strong Allee effects, can vary over space and time but few empirical studies have examined this variation. A lack of geographically extensive, long-term studies on low density population dynamics makes studying variability in Allee effects difficult. We used North American gypsy moth population data from 1996-2016 to quantify Allee thresholds in 11 regions of the invasion front. Allee thresholds spanned a continuum from being undetectable due to strong population growth at all densities, to being unmeasurable because populations declined across all densities. The lag-1 temporal autocorrelation …