Abstract
Many species are too slow to track their poleward-moving climate niche under global warming. Pesticide exposure may contribute to this by reducing population growth and impairing flight ability. Moreover, edge populations at the moving range front may be more vulnerable to pesticides because of the rapid evolution of traits to enhance their rate of spread that shunt energy away from detoxification and repair. We exposed replicated edge and core populations of the poleward-moving damselfly Coenagrion scitulum to the pesticide esfenvalerate at low and high densities. Exposure to esfenvalerate had strong negative effects on survival, growth rate, and development time in the larval stage and negatively affected flight-related adult traits (mass at emergence, flight muscle mass, and fat content) across metamorphosis. Pesticide effects did not differ between edge and core populations, except that at the high concentration the pesticide-induced mortality was 17% stronger in edge populations. Pesticide exposure may therefore slow down the range expansion by lowering population growth rates, especially because edge populations suffered a higher mortality, and by negatively affecting dispersal ability by impairing flight-related traits. These results emphasize the need for direct conservation efforts toward leading-edge populations for facilitating future range shifts under global warming.
Highlights
Global warming is causing widespread poleward range expansions where species try to keep pace with their moving climate niche (Hickling et al 2006; Chen et al 2011)
Contrasts analyses showed that at the high esfenvalerate concentration the pesticide-induced mortality was stronger in edge populations than in core populations (F1,70 = 8.03, P = 0.006, Fig. 1), while mortality did not differ between edge and core populations in the control (F1,70 < 0.01, P = 0.99) and at the low concentration (F1,70 = 0.37, P = 0.54)
Main effects of the pesticide We found strong negative effects of larval exposure to the ecologically realistic esfenvalerate concentrations on all studied traits in the larval and in the adult stage, and this despite the long period that larvae were able to recover from pesticide exposure
Summary
Global warming is causing widespread poleward range expansions where species try to keep pace with their moving climate niche (Hickling et al 2006; Chen et al 2011). Under ongoing and more intense global warming, rangeexpanding species are expected to continue to move more poleward to track their optimal thermal niche (Hickling et al 2006; Chen et al 2011). Understanding factors shaping the speed of range expansion is timely as there is increasing concern that many species are too slow to track their moving climate niche (Razgour et al 2013).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
