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In order to evaluate the effects of insecticides residues in soil substrates on the biology cycle of Aedes aegypti, we conducted a study in three ecological zones: urban areas (Dandji, southern Benin with few agriculture activities), peri urban areas (Awaya, central of Benin with agriculture practices), and forests (Kaoura, northern Benin with few agriculture activities). These areas were chosen because they provided an ideal environment for the development of Aedes aegypti. The purpose of this study is to look for insecticide residues that may have detrimental impacts on the biology cycle of A. aegypti. Indirect bioassays were used to investigate the factors affecting mosquito larvae’s ability to develop normally at breeding sites, their rate of growth, and their ability to produce an adequate number of larvae. Due to the absence of an HPLC equipment for the direct detection of pesticide residues in samples, A. aegypti larvae at breeding sites were reconstituted using water and soil samples obtained at each study site. A comparison of the larval growth in test breeding locations was made using the reference strain SBE as a control. The different bioassays demonstrate the existence of inhibitory elements on test materials. In control samples, larval development was observed to be normal. However, when the breeding sites were established with just a few grams of soil samples from the three study sites, it was found that the A. aegypti eggs had a poor hatching rate, along with sluggish larval development and a low production of adult mosquitoes from hatched eggs. The findings of this study indicate that toxic substances that prevent A. aegypti eggs from hatching and larvae from growing are most likely leftover pesticides from agricultural operations. In order to quantify the toxic factors likely to affect the biology parameters of A. aegypti cited above, these results must be validated using HPLC techniques. Published by the Journal of Biodiversity and Environmental Sciences | JBES, {"references":["Amelia-Yap ZH, Chen CD, Sofian-Azirun M, Low VL. 2018. Pyrethroid Resistance in the Dengue Vector Aedes aegypti in Southeast Asia: Present Situation and Prospects for Management. Parasites & Vectors 11(1), 332p.","Carletto J, Martin T, Flavie Vanlerberghe-Masutti F, Brévault M. 2010. Insecticide Resistance Traits Differ among and within Host Races in Aphis gossypii. Pest Management Science 66(3), 301‑7.","Fagbami AH, Onoja AB. 2018. Dengue Haemorrhagic Fever: An Emerging Disease in Nigeria, West Africa. Journal of Infection and Public Health 11(6), 757‑62.","Fofana D, Beugré JMV, Yao-Acapovi G, Lendzele SS. 2019. Risk of Dengue Transmission in Cocody (Abidjan, Ivory Coast). Journal of Parasitology Research 2019: 4914137.","Gaye A, Ndiaye C, Sy M, Deme A, Thiaw AB, Sene A, Ndiaye C, Diedhiou Y, Mbaye A, Ndiaye A, Tomkins-Tinch C, Gomis J, Badiane AS, Maclnnis B, Park D, Ndiaye M, Sy N, Sabeti PC, Siddle KJ and Ndiaye D. 2021. Genomic Investigation of a Dengue Virus Outbreak in Thiès, Senegal in 2018. Scientific Reports 11(1), 10321p.","Linnaeus. 1762. Aedes aegypti (Linnaeus, 1762). Walter Reed Biosystematics Unit (WRBU).","Lounibos L, Juliano SA. 2018. Where Vectors Collide: The Importance of Mechanisms Shaping the Realized Niche for Modeling Ranges of Invasive Aedes Mosquitoes. Biological Invasions 20(8), 1913‑1929.","Martín MA, Siles JA, Martin A. 2010. Biomethanization of Orange Peel Waste. Bioresource Technology 101(23), 8993‑8999.","Ouédraogo S, Degroote S, Barro SA, Some PA, Bonnet E and Ridde V. 2019. Recurrence of dengue epidemics in Burkina Faso: Community preference for an intervention to prevent the disease. Rev Epidemiol Sante Publique 67(6), 375‑382.","WHO. 2009. Dengue guidelines for diagnosis, Treatment, Prevention and Control.","Yadouleton A, Agbanrin R, Vodounon C, Padonou G, Badirou K, Attolou R, Ursins F, Zola J, Allagbé H, Akogbéto M. 2014. Seasonal Distribution of Aedes aegypti in Southern Benin: A Risk of Dengue Virus Transmission to Urban Populations. International Journal of Innovation and Applied Studies 9 (2), 648‑654.","Yadouleton A, Thibaud M, Padonou G, Fabrice C, Alex A, Djogbenou L, Roch D, Aikpon R, Boko M, Glitho I, Akogbeto M. 2011. Cotton pest management practices and the selection of pyrethroid resistance in Anopheles gambiae population in Northern Benin ». Parasites & Vectors 4(1), 60p."]}

Insecticide treatments for crop protection have often be cited as the main factor of the resistance selection of Aedes aegypti. This is however the main vector dengue fever. To verify this hypothesis, bioassay tests was performed on adults collected from the field (2 urban and 2 rural areas) at Natitingou to assess the susceptibility of dengue vectors to insecticideimpregnated papers (permethrin 0.75%, delthamethrin 0.05%, lambdacyalothrin 0.05%, DDT 4%, and bendiocarb 0.1%) following WHO Pesticide Evaluation Scheme. Results from this study showed that Ae. Aegypti populations were resistant to DDT and pyrethroids with 12% and 38% respectively as mean of mortality despite the areas of mosquitoes collection. However, they were fully susceptible to bendiocarb. Our study showed that Aedes aegypti populations had developed resistance to organochlorine and pyrethroids, but are susceptible to carbamate. The low mortality rate recorded in all populations of Ae. Aegypti with bendiocarb is encouraging in regards to the use of this insecticide as an alternative in case of outbreak of dengue fever in this district of Benin.

In order to evaluate the trophic behavior of Aedes aegypti in the city of Cotonou, southern Benin, a cross-sectional study was conducted in urban and periurban neighborhoods from April 2016 to August 2017 to collect Ae. Aegypti populations. To achieve this goal, day and night collections, twice a month for one year were done where Ae. Aegypti populations were caught by Human Landing Catch and BG-Sentinel traps. 3,892 Aedes caught by different methods showed that Ae. Aegypti and Ae. circumluteolus are more abundant in urban than peri-urban areas (p