Canadian Forest Service Publications
Supraoptimal temperatures influence the range dynamics of a non-native insect. 2014. Tobin, P.C.; Gray, D.R.; Liebhold, A.M. Diversity and Distributions 20(7): 813-823.
Issued by: Atlantic Forestry Centre
Catalog ID: 35605
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We linked the annual frequency of supraoptimal temperatures during the larval and pupal period of L. dispar with annual changes in its range dynamics based upon a spatially robust 20-year dataset. Correlation analyses were used to estimate the association between exposure time above the optimal temperature for L. dispar larval and pupal development, and the rate of invasion spread when adjusted for spatial autocorrelation. We documented L. dispar range expansion, stasis, and retraction across a fairly narrow latitudinal region. We also observed differences in the amount of exposure above the optimal temperature for L. dispar larval and pupal development across this region. Temperature regimes in the Coastal Plain and Piedmont regions of Virginia, where the L. dispar range has retracted or remained static, were warmer than those in the Appalachian Mountains of Virginia and West Virginia, where L. dispar has expanded its range. Our analyses at a smaller spatial scale confirmed a statistically negative association between exposure time above the optimal temperature for L. dispar larvae and pupae, and the rate of L. dispar invasion spread over the 20-year period. The shifting, expansion and retraction of species distributional ranges holds critical implications to both invasion ecology and conservation biology. This work provides novel empirical evidence of the importance of supraoptimal temperatures on the range dynamics of a non-native invasive insect with application to both non-native and native species whose physiological processes are strongly regulated by temperature.
Plain Language Summary
An insect species can only occur where the climate consistently falls within the limits of tolerance of the species. The range of the species is expected to retract when there is an increase in the frequency of temperatures that are either too cold, or too hot. The authors provide the first data-driven evidence of a retraction of the range of an invading insect species due to an increase in the frequency of temperatures that are too hot.