Cross-Generational Effects of Heat Stress on Fitness and Wolbachia Density in Aedes aegypti Mosquitoes.

mosquitoes infected with symbionts are now being released into the field to control the spread of pathogenic human arboviruses. can spread throughout vector populations by inducing cytoplasmic incompatibility and can reduce disease transmission by interfering with virus replication. The success of this strategy depends on the effects of on mosquito fitness and the stability of infections across generations. infections are vulnerable to heat stress, and sustained periods of hot weather in the field may influence their utility as disease control agents, particularly if temperature effects persist across generations. To investigate the cross-generational effects of heat stress on density and mosquito fitness, we subjected with two different infection types (Mel, AlbB) and uninfected controls to cyclical heat stress during larval development over two generations. We then tested adult starvation tolerance and wing length as measures of fitness and measured the density of Mel in adults. Both heat stress and infection reduced adult starvation tolerance. Mel density in female offspring was lower when mothers experienced heat stress, but male density did not depend on the rearing temperature of the previous generation. We also found cross-generational effects of heat stress on female starvation tolerance, but there was no cross-generational effect on wing length. Fitness costs of infections and cross-generational effects of heat stress on density may reduce the ability of to invade populations and control arbovirus transmission under specific environmental conditions.