The role of temperature in shaping Culex acharistus mosquitoes life history traits in its southern limit of distribution (Patagonia-Argentina)

• Published in: Heliyon 2023-02, Vol.9 (2), p.e13696, Article e13696
• Main Authors: Grech, M.G., Miserendino, M.L., Almirón, W.R.
• Format: Article
• Language: English
• Subjects: Natural fluctuating temperature; Physiological time; Temperate region; Temperature development threshold; Vital statistics
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2023.e13696

There is substantial evidence showing that temperature have a great impact on insects behavior, phenology and life histories. Because of mosquito global importance as disease vectors, in temperate regions where climatic conditions could be only borderline suitable for mosquito development, there is a growing interest in understanding the effect of temperature shifts on vital statistics to more accurately define how such changes could impact distribution and abundance patterns, as well as disease transmission cycles. We determined the role of ambient temperature under fluctuating conditions in shaping Culex acharistus (Diptera: Culicidae) life history traits, and estimated its development threshold and physiological time, in its southern limit of distribution in the Argentine Patagonia region. Four horizontal life tables were conducted under natural fluctuating temperature range in Esquel city (42°S – 71°W; 563 m a.s.l.), during spring-summer (17°C), summer (15.4°C), summer-autumn (12.7°C) and autumn-winter (5.6°C) seasons. Larvae, pupae and adult traits were recorded. The mean duration of the experiments varied between 28 to ≅100 days for spring-summer and autumn-winter seasons. Only during the cold season experiment pupae experienced the most severe temperatures and freeze-thaw cycles, and failed to reach adult stage. We found that larva and pupa development time, adult emergence time and longevity significantly increased with decreasing temperatures, while larval survival was greatest at an intermediate temperature and decreased toward low and high values. Also, protandry was observed and males emerge 2 days before females across seasons. Temperature development threshold and physiological time estimated for larva + pupa were 5.98°C and 211.24°C-days. Our study contributes to a growing body of knowledge by examining the effect of seasonal changes in temperature on mosquito life history traits. Results obtained here can be applied as useful parameters in the development of population dynamic models, improving current mosquito control strategies in cold-temperate regions. [Display omitted] •Seasonal changes in temperature had a pronounced effect on larvae, pupae and adult traits.•Larva and pupa development time, adult emergence time and longevity increased with decreasing temperatures.•Larval survival was greatest at 12.7°C and decreased toward low and high values.•Temperature development threshold was 5.98°C.•Physiological time was 211.24°-days.