The Field Assessment of Quiescent Egg Populations of Aedes aegypti and Aedes albopictus during the Dry Season in Tapachula, Chiapas, Mexico, and Its Potential Impact on Vector Control Strategies.

Simple Summary: The role of mosquito eggs in disease transmission is not well understood, despite reports of virus vertical transmission and their ability to survive dry periods in a dormant stage. Additionally, field evidence shows that new generations of mosquitoes often reappear weeks or months later in certain city areas. This may be because both species follow an "R strategy" reproduction pattern, laying many eggs to ensure survival in a harsh environment. This study was conducted in southern Mexico in 2023 and focused on the egg-laying activity of Ae. aegypti and Ae. albopictus mosquitoes during the dry inter-epidemic season. Ovitraps were used in the backyards of the houses to identify egg species, and further larval containers were surveyed. Most of the larval habitats were containers smaller than 1 L, commonly not treated as they were considered trash. Even though homeowners volunteer to remove them during government cleaning community-based campaigns, city waste disposal trucks transporting these containers do not take any measures to destroy the tiny eggs. We conclude with the urgent need to develop an egg-killing treatment, which could significantly enhance vector reduction and achieve a total stage strategy within the Integrated Vector Control Programs. Although integrated management and control programs implement intense control measures for adult, pupal, larval, and breeding sites during outbreaks, there is a lack of studies to understand the role of the vector egg stage in disease dynamics. This study aimed to assess the dry season quiescent Aedes aegypti and Aedes albopictus egg populations in houses and backyards in Tapachula, southern Mexico. Two hundred and fifty ovitraps were placed in 125 homes in the Las Americas neighborhood. A total of 7290 eggs were collected from 211 (84.4%) ovitraps. Only 5667 (77.7%) hatched under insectary water immersion and food supply conditions, with 4031 (71.1%) identified as Ae. aegypti, and 1636 (28.8%) as Ae. albopictus, respectively. The remaining 1623 (22.3%) did not hatch due to Delayed Hatching and/or quiescence tropical stage. Eighty-three larval containers were sampled with desiccated eggs during the dry season; most of them were described as trash waste because larvicides are only used for larger containers of 5–10 L. Evolutionary characteristics for the two species including partial egg hatching, ambient-regulated quiescence, the ability of the embryo to survive for a more extended period intra-seasonally, the egg sticking to inner container walls, demands urgent operational research to achieve successful egg-proof larval container methods. [ABSTRACT FROM AUTHOR]