Aedes aegypti control programs require more sensitive tools in order to survey domestic and peridomestic larval habitats for dengue and other arbovirus prevention areas. As a consequence of the COVID-19 pandemic, field technicians have faced a new occupational hazard during their work activities in dengue surveillance and control. Safer strategies to monitor larval populations, in addition to minimum householder contact, are undoubtedly urgently needed. Drones can be part of the solution in urban and rural areas that are dengue-endemic. Throughout this study, the proportion of larvae breeding sites found in the roofs and backyards of houses were assessed using drone images. Concurrently, the traditional ground field technician’s surveillance was utilized to sample the same house groups. The results were analyzed in order to compare the effectiveness of both field surveillance approaches. Aerial images of 216 houses from El Vergel village in Tapachula, Chiapas, Mexico, at a height of 30 m, were obtained using a drone. Each household was sampled indoors and outdoors by vector control personnel targeting all the containers that potentially served as Aedes aegypti breeding sites. The main results were that the drone could find 1 container per 2.8 found by ground surveillance; however, containers that were inaccessible by technicians in roofs and backyards, such as plastic buckets and tubs, disposable plastic containers and flowerpots were more often detected by drones than traditional ground surveillance. This new technological approach would undoubtedly improve the surveillance of Aedes aegypti in household environments, and better vector control activities would therefore be achieved in dengue-endemic countries.

Aedes aegypti is widely distributed worldwide and is the main vector mosquito for dengue, one of the most important infectious diseases in middle- and low-income countries. The landscape composition and vegetation cover determine appropriate environments for this mosquito to breed, and it is fundamental to define the most affordable methodology to understand these landscape variables in urban environments. The proposed methodology integrated drone technologies and traditional entomological surveillance to strengthen our knowledge about areas suitable for Ae. aegypti infestation. We included an analysis using the vegetation indexes, NDVI and NDVIRe, and their association with Ae. aegypti larvae and adults in houses from the El Vergel neighborhood Tapachula, Chiapas, Mexico. We used drone technology to obtain high-resolution photos and performed multispectral orthomosaic constructions for the data of vegetation indexes with a kernel density analysis. A negative binomial regression was performed to determine the association between the numbers of Ae. aegypti larvae and adults with the kernel density based on NDVI and NDVIRe. Medium and high values of kernel density of NDVIRe (both p-value < 0.05) and NDVI (both p-value < 0.05) were associated with a higher amount of mosquito adults per houses. The density of Ae. aegypti larvae per house did not show an association with medium and high values of NDVIRe (both p-value > 0.05) and NDVI (both p-value > 0.05). The vegetation indexes, NDVI and NDVIRe, have potential as precise predictors of Ae. aegypti adult mosquito circulation in urban environments. Drone technology can be used to map and obtain landscape characteristics associated with mosquito abundance in urban environments.

Objetivo. Estimar la diversidad de garrapatas, la prevalencia de infestación y tasa de infección de Rickettsia spp. en ganado bovino en la costa del estado de Chiapas. Material y métodos. Se realizó un estudio transversal de octubre de 2021 a marzo de 2022, que incluyó la extracción de garrapatas de 297 vacas pertenecientes a 5 municipios. Se calcularon los índices de diversidad. El diagnóstico de Rickettsia spp en las garrapatas se realizó mediante PCR anida. Resultados. Se encontró una baja diversidad de especies. Las especies Rhipicephalus microplus, Amblyomma cajennense y Rhipicephalus sanguineus hembra adultas fueron positivas a Rickettsia spp. Los municipios de Pijijiapan y Tonalá presentaron la TMI más alta con 7.5 y 7.2%. Conclusión. Este es primer estudio México que reporta infección de Rickettsia spp, en garrapatas colectadas de ganado bovino, lo cual indica un riesgo de salud pública.

Objective. To assess larvicide and adulticide activity of different native strains of fungi on Aedes aegypti. Materials and methods. Third instar larvae were exposed for 72 h at a concentration of 1x108 conidia/ml of 15 fungi; only fungi that significantly affected the larvae were evaluated against the adult phase at a concentration of 2x1010 conidia/ml. Mortality readings were performed at 24, 48, and 72 h for larvae, and every day to 30 days for adults. Results. Trichoderma longibrachiatum, Aspergillus aculeatus, and Metarhizium anisopliae had the best larvicidal activity at 24 h of exposure (p<0.05), causing mortalities of 100, 72, and 62%, respectively. Adult mosquitoes were more affected by Gliocladium virens (45% mortality), M. anisopliae (30% mortality), and T. longibrachiatum (23.33% mortality). Conclusion. The larval stage of Ae. aegypti was more susceptible than the adult phase to the pathogenic action of native fungi, with T. longibrachiatum being with the highest virulence. Objective. To assess larvicide and adulticide activity of different native strains of fungi on Aedes aegypti. Materials and methods. Third instar larvae were exposed for 72 h at a concentration of 1x108 conidia/ml of 15 fungi; only fungi that significantly affected the larvae were evaluated against the adult phase at a concentration of 2x1010 conidia/ml. Mortality readings were performed at 24, 48, and 72 h for larvae, and every day to 30 days for adults. Results. Trichoderma longibrachiatum, Aspergillus aculeatus, and Metarhizium anisopliae had the best larvicidal activity at 24 h of exposure (p<0.05), causing mortalities of 100, 72, and 62%, respectively. Adult mosquitoes were more affected by Gliocladium virens (45% mortality), M. anisopliae (30% mortality), and T. longibrachiatum (23.33% mortality). Conclusion. The larval stage of Ae. aegypti was more susceptible than the adult phase to the pathogenic action of native fungi, with T. longibrachiatum being with the highest virulence.

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.

Surveillance consists of systematic data collection, analysis, and interpretation and is essential for planning and implementing control activities. The lack of success in the control and surveillance of the Ae. aegypti mosquito elsewhere demands the development of new accessible and effective strategies. This work aimed to develop and evaluate an adhesive lure trap for household indoor surveillance of Ae. aegypti. Based on a bibliographic review, four compounds that have significant attraction percentages for Ae. aegypti were considered. Our more effective blend was determined through preliminary bioassays using the high-throughput screening system (HITSS) and 90 × 90 cm mosquito cages. We designed a low-cost, pyramid-shaped, sticky cardboard trap to incorporate the selected blend. Semi-field 2 × 2 m cages and field tests were utilized to evaluate its effectiveness through mosquito capture percentages. In laboratory tests, blend number 2 presented an attraction percentage of 47.5 ± 4.8%; meanwhile, in semi-field cages, a 4-inch, 110 v powered fan was used to disperse the attractants, and then a similar capture percentage of 43.2 ± 4.0% was recorded. Results were recorded during the field evaluation of the at-house indoor environment and were compared with those recorded with the golden-standard BG-Sentinel trap, i.e., our prototype trapped an average of 6.0 ± 1.5 mosquitoes versus 10.0 ± 2.6. In most Latin American countries, there is a lack of formal and accessible strategies for monitoring adult populations of Ae. Aegypti; therefore, we must develop tools that reinforce entomological surveillance methods.