Jana Celina Ríos-Delgado

Dengue outbreaks highlight the need to quantify how environments sustain populations of the mosquito vectors Ae. aegypti and Ae. albopictus. Most control activities focus on households, while non-residential premises receive little attention. We conducted a cross-sectional ovitraps survey in August 2025 in Tapachula, Chiapas, Mexico, deploying 593 ovitraps: 297 in residential neighborhoods and 293 in non-residential sites. We collected 42,758 eggs; 61.5% (n = 26,316) came from residential areas and 38.5% (n = 16,442) from non-residential areas. Ovitrap positivity was higher in residential versus in non-residential areas (92.6% vs. 87.0%; p = 0.025), and the mean number of eggs per ovitrap (88.6 ± 5.1 vs. 56.1 ± 3.3 eggs; p < 0.001), yielding 298.0 vs. 175.3 eggs/ha, respectively. From a subsample of 16,965 eggs, 7,543 adults emerged (44.5%), dominated by Ae. aegypti in residential areas (83.3%) and Ae. albopictus in non-residential areas (80.0%). Vector burden differed by species: Ae. aegypti densities were higher in residential areas (51.0 vs. 4.5 adults/ha), whereas Ae. albopictus densities were higher in non-residential sites (18.2 vs. 10.2 adults/ha). These patterns show that both residential and non-residential premises are important sources of dengue vectors and should be included in integrated surveillance and control strategies.

Objective. To development of a methodology for the chilling, handling, transport, and release of male Aedes aegypti mosquitoes, reared in insectary conditions to release in the field with unmanned vehicles to compete sexually with wild males in the field. Materials and methods. A population of Ae. aegypti from different areas in Tapachula, Chiapas, was used. Laboratory tests were conducted: Effect of temperature and cooling time on the knockdown, recovery of males, and copulatory success. Results. The chilling temperature of 3 ± 1ºC for 30 min, was used as a knockdown temperature before handling, packing, transportation, and aerial release. The males subjected to the entire process, including the semi-field aerial release test, showed normal sexual behavior activity, obtaining 100% of females inseminated. Conclusion. These results present the feasibility of applying a new control methodology using unmanned aerial vehicle (UAV) as support for the sterile insect release technique (SIT), use of Wolbachia or both, in male Ae. aegypti, for the design of strategies to control their populations.

Anopheles darlingi is considered the most efficient malaria vector in the Neotropical region. In Mexico, its role as an incriminated vector of Plasmodium has not been confirmed in the Lacandon forest. Similarly, knowledge about bionomic and larval ecology is scarce. The study aim was to identify and describe the larval habitats of An. darlingi in Chiapas, México. Standard larval collections were performed in the Lacandon forest region and in the Soconusco region of southern Chiapas from January 2010 to April 2014, including dry and rainy seasons. Mean larval density of An. darlingi was estimated according to hydrological types, and associations between the presence of An. darlingi and environmental factors including ecological parameters and geographic positions were statistically analysed. One hundred and twelve aquatic habitats were analysed, 80 from the Lacandon forest region and 32 from the Soconusco region; 94.64 % of these sites presented anopheline larvae. In total, 10,977 larvae belonging to 11 Anopheles species were collected. The 19 (out of 112) larval habitats positive to An. darlingi were: rain puddles (26.32 %), ground pools (21.05 %), ponds (15.79 %), ditches (15.79 %), river margins (10.53 %) and streams (10.53 %). Overall, the average (±SD) larval density was 6.60 ± 2.41 larvae per dip. Multiple logistic regression analysis showed that temporary habitats, green algae presence and stagnant water were associated with An. darlingi larval presence. The positive habitats were found in the Lacandon forest region during the rainy season (May–September). No specimens were found in the Soconusco region of the coastal plain of Chiapas. The mosquito An. darlingi larval habitats were found in different hydrological types. The habitat stability, presence of algae and water current were the main factors for An. darlingi larval occurrence. The information on the characteristics of the larval habitats of An. darlingi will be useful in sustainable programmes for malaria control in the Lacandon forest region, Chiapas.