An impressive capacity for cold tolerance plasticity protects against ionoregulatory collapse in the disease vector,Aedes aegypti

Abstract

141. The mosquito Aedes aegypti is largely confined to tropical and subtropical regions but its 15 range has recently been spreading to colder climates. As insect biogeography is closely 16 tied to environmental temperature, understanding the limits of Ae. aegypti thermal 17 tolerance and their capacity for phenotypic plasticity is important in predicting the spread 18 of this species. 19 2. In this study we report on the chill coma onset and recovery, as well as low temperature 20 survival phenotypes of larvae and adults of Aedes aegypti that developed or were 21 acclimated to 15°C (cold) or 25°C (warm). 22 3. Developmental cold acclimation did not affect chill coma onset of larvae but substantially 23 reduced chill coma onset temperatures in adults. Chill coma recovery time was affected 24 by both temperature and the duration of exposure, and developmental and adult 25 acclimation both strongly mitigated these effects and increased rates of survival following 26 prolonged chilling.27 4. Female adults were far less likely to take a blood meal when cold acclimated and simply 28 exposing females to blood (without feeding) attenuated some of the beneficial effects of 29 cold acclimation on chill coma recovery time. 30 5. Lastly, larvae suffered from hemolymph hyperkalemia when chilled, but development in 31 the cold attenuated the imbalance, which suggests that acclimation can prevent cold-32 induced ionoregulatory collapse in this species. 33 6. Our results demonstrate that Aedes aegypti larvae and adults have the capacity to 34 acclimate to cold temperatures and do so at least in part by better maintaining ion balance 35 in the cold. This ability for cold acclimation may facilitate the spread of this species to 36 higher latitudes, particularly in an era of climate change.37 38 Low temperatures adversely affect life history traits throughout the Ae. aegypti life cycle, 61 including development rate, reproductive success, and survival (Carrington, Armijos, 62

Temperature modulates immune gene expression in mosquitoes during arbovirus infection

“…Mosquitoes have evolved various strategies to cope with different thermal conditions such as acclimation, adjusting behavioural activity and synthesis of heat shock proteins [54][55][56]. The downregulation at 32°C and 7 dpi of two sensory genes, namely odorant binding protein and long wavelength opsin, suggest a possible effect on mediators of behavioural activity.…”

Size, not temperature, drives cyclopoid copepod predation of invasive mosquito larvae

“…A recent study showed that Ae. aegypti larvae from a colony maintained at 22 ± 1°C continued to move in response to probing as the temperature was gradually lowered; the larvae did not stop responding with movement until the temperature reached 6°C, 16°C lower than the temperature at which their colony was maintained (Jass et al, 2019). From a public health perspective, the absence of significantly lower predation efficiency at lower temperatures is useful because Ae.…”

Post-Embryonic Development ofAedes(Stegomyia)aegyptiLinnaeus, 1762 at Different Temperatures and CO2Concentrations, and Their Influences on Hatching and Development of Stabilized Population

“…Thus, it is evident that the life cycle of the mosquitoes in Londrina is also affected only in extreme temperatures, in view of the greater number of emergencies of adults of A. aegypti observed at 5°C (44.80%), as well as a relatively low mortality rate on this temperature (6.6%). The ability of A. aegypti larvae and adult to tolerate low temperatures also was demonstrated in the study by Jass et al [41].…”