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Source: http://www.plosone.org/article/info%...l.pone.0058824
Effects of Fluctuating Daily Temperatures at Critical Thermal Extremes on Aedes aegypti Life-History Traits
Lauren B. Carrington mail,
M. Veronica Armijos,
Louis Lambrechts,
Christopher M. Barker,
Thomas W. Scott
Abstract
Background
The effect of temperature on insect biology is well understood under constant temperature conditions, but less so under more natural, fluctuating conditions. A fluctuating temperature profile around a mean of 26?C can alter Aedes aegypti vector competence for dengue viruses as well as numerous life-history traits, however, the effect of fluctuations on mosquitoes at critical thermal limits is unknown.
Methodology/Principal Findings
We investigated the effects of large and small daily temperature fluctuations at low (16?C) and high (35?37?C) mean temperatures, after we identified these temperatures as being thresholds for immature development and/or adult reproduction under constant temperature conditions. We found that temperature effects on larval development time, larval survival and adult reproduction depend on the combination of mean temperature and magnitude of fluctuations. Importantly, observed degree-day estimates for mosquito development under fluctuating temperature profiles depart significantly (around 10?20%) from that predicted by constant temperatures of the same mean. At low mean temperatures, fluctuations reduce the thermal energy required to reach pupation relative to constant temperature, whereas at high mean temperatures additional thermal energy is required to complete development. A stage-structured model based on these empirical data predicts that fluctuations can significantly affect the intrinsic growth rate of mosquito populations.
Conclusions/Significance
Our results indicate that by using constant temperatures, one could under- or over-estimate values for numerous life-history traits compared to more natural field conditions dependent upon the mean temperature. This complexity may in turn reduce the accuracy of population dynamics modeling and downstream applications for mosquito surveillance and disease prevention.
Citation: Carrington LB, Armijos MV, Lambrechts L, Barker CM, Scott TW (2013) Effects of Fluctuating Daily Temperatures at Critical Thermal Extremes on Aedes aegypti Life-History Traits. PLoS ONE 8(3): e58824. doi:10.1371/journal.pone.0058824
Editor: Nikos Vasilakis, University of Texas Medical Branch, United States of America
Received: December 18, 2012; Accepted: February 7, 2013; Published: March 8, 2013
Effects of Fluctuating Daily Temperatures at Critical Thermal Extremes on Aedes aegypti Life-History Traits
Lauren B. Carrington mail,
M. Veronica Armijos,
Louis Lambrechts,
Christopher M. Barker,
Thomas W. Scott
Abstract
Background
The effect of temperature on insect biology is well understood under constant temperature conditions, but less so under more natural, fluctuating conditions. A fluctuating temperature profile around a mean of 26?C can alter Aedes aegypti vector competence for dengue viruses as well as numerous life-history traits, however, the effect of fluctuations on mosquitoes at critical thermal limits is unknown.
Methodology/Principal Findings
We investigated the effects of large and small daily temperature fluctuations at low (16?C) and high (35?37?C) mean temperatures, after we identified these temperatures as being thresholds for immature development and/or adult reproduction under constant temperature conditions. We found that temperature effects on larval development time, larval survival and adult reproduction depend on the combination of mean temperature and magnitude of fluctuations. Importantly, observed degree-day estimates for mosquito development under fluctuating temperature profiles depart significantly (around 10?20%) from that predicted by constant temperatures of the same mean. At low mean temperatures, fluctuations reduce the thermal energy required to reach pupation relative to constant temperature, whereas at high mean temperatures additional thermal energy is required to complete development. A stage-structured model based on these empirical data predicts that fluctuations can significantly affect the intrinsic growth rate of mosquito populations.
Conclusions/Significance
Our results indicate that by using constant temperatures, one could under- or over-estimate values for numerous life-history traits compared to more natural field conditions dependent upon the mean temperature. This complexity may in turn reduce the accuracy of population dynamics modeling and downstream applications for mosquito surveillance and disease prevention.
Citation: Carrington LB, Armijos MV, Lambrechts L, Barker CM, Scott TW (2013) Effects of Fluctuating Daily Temperatures at Critical Thermal Extremes on Aedes aegypti Life-History Traits. PLoS ONE 8(3): e58824. doi:10.1371/journal.pone.0058824
Editor: Nikos Vasilakis, University of Texas Medical Branch, United States of America
Received: December 18, 2012; Accepted: February 7, 2013; Published: March 8, 2013