This study evaluated how short-term sublethal heat shocks affect reproductive outcomes in three mosquito species. The authors exposed males or females at different developmental stages to brief high-temperature treatments and measured multiple aspects of reproductive performance. The aim was to determine whether short, non-lethal heat events compromise fertility and whether effects differ by species, sex, life stage or timing of exposure.
Three species were examined: Aedes aegypti, Aedes notoscriptus, and Culex quinquefasciatus. Individuals of each species were exposed to heat shock during either the pupal stage or the adult stage, and exposures were applied separately to males and females to assess sex-specific sensitivity.
Reproductive performance was quantified using several outcomes: egg-laying success, female fecundity (egg numbers), egg hatchability, and production of viable offspring. These metrics allowed the authors to capture both immediate reproductive outputs and the eventual contribution to the next generation.
Across the three species, female heat shock produced limited effects on measured fertility outcomes. A notable exception was seen in Ae. notoscriptus, where exposing adult females to 41 °C for 1 hour reduced production of viable offspring. Otherwise, female exposures—whether at pupal or adult stages—had generally minor impacts on egg-laying success, fecundity or hatchability in the species studied.
Male heat shock effects were more variable and were species- and stage-dependent. In Culex quinquefasciatus, male heat exposure reduced egg hatchability, indicating compromised male-driven fertilization outcomes or sperm viability. In Ae. aegypti, male heat exposure reduced viable offspring production, and the magnitude depended on whether the pupal or adult life stage was exposed. These findings show that male thermal sensitivity can influence downstream measures of fertility differently across species.
The authors conducted several additional experiments focused on Ae. aegypti to explore the dynamics and mechanisms of heat-induced fertility changes. Key observations in this species included partial recovery of male fertility after heat exposure, persistent female effects regardless of mating timing, and transgenerational responses when mothers experienced heat shock.
In Ae. aegypti, male fertility did not remain permanently impaired after heat shock. Male reproductive performance partially recovered within 24–48 hours following exposure, indicating some temporal reversibility of heat-induced impairment in males. The source text reports this recovery interval but does not include detailed recovery curves, sample sizes or statistical measures in the abstract.
Maternal heat shock exposure produced an unexpected positive effect under subsequent stress: offspring of heat-exposed mothers showed enhanced fecundity and greater production of viable offspring when those offspring were later subjected to sublethal heat stress. This maternal effect suggests potential plastic or transgenerational responses that can influence population-level resilience under sequential thermal challenges.
Overall, the findings indicate that short-term, sublethal heat shocks are largely tolerable with respect to mosquito fertility across the tested species, but outcomes are nuanced. Effects depend on species, sex, developmental stage, timing relative to mating, and which reproductive trait is measured. These complexities are important when predicting mosquito population persistence and species survival under increasing frequency of heat extremes linked to climate change. The study highlights that some reproductive traits and demographic outcomes may remain stable after brief heat events, while others could be transiently or selectively impacted.
The provided source text is an abstract from a preprint and summarizes main findings without full methodological detail. Specific experimental parameters beyond the example of 41 °C for 1 hour, such as exact temperature regimes for all tests, sample sizes, statistical analyses, and full protocols, were not reported in the abstract. The source notes funding support and the absence of declared competing interests, but readers should consult the full preprint for complete methods, data and statistical results.