Title of article :
Acclimation effects on critical and lethal thermal limits of workers of the Argentine ant, Linepithema humile
Author/Authors :
Jumbam، نويسنده , , Keafon R. and Jackson، نويسنده , , Susan and Terblanche، نويسنده , , John S. and McGeoch، نويسنده , , Melodie A. and Chown، نويسنده , , Steven L.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2008
Pages :
7
From page :
1008
To page :
1014
Abstract :
For the Argentine ant Linepithema humile, bioclimatic models often predict narrower optimal temperature ranges than those suggested by behavioural and physiological studies. Although water balance characteristics of workers of this species have been thoroughly studied, gaps exist in current understanding of its thermal limits. We investigated critical thermal minima and maxima and upper and lower lethal limits following acclimation to four temperatures (15, 20, 25, 30 °C; 12L:12D photoperiod) in adult workers of the Argentine ant, L. humile, collected from Stellenbosch, South Africa. At an ecologically relevant rate of temperature change of 0.05 °C min−1, CTMax varied between 38 and 40 °C, and CTMin varied between 0 and 0.8 °C. In both cases the response to acclimation was weak. A significant time by exposure temperature interaction was found for upper and lower lethal limits, with a more pronounced effect of acclimation at longer exposure durations. Upper lethal limits varied between 37 and 44 °C, whilst lower lethal limits varied between −4 and −10.5 °C, with an acclimation effect more pronounced for upper than lower lethal limits. A thermal envelope for workers of the Argentine ant is provided, demonstrating that upper thermal limits do likely contribute to distributional limits, but that lower lethal limits and limits to activity likely do not, or at least for workers who are not exposed simultaneously to the demands of load carriage and successful foraging behaviour.
Keywords :
Bioclimatic modelling , Acclimation , Critical thermal limits , Knockdown temperature , Thermal tolerance
Journal title :
Journal of Insect Physiology
Serial Year :
2008
Journal title :
Journal of Insect Physiology
Record number :
1414920
Link To Document :
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