Background/Objectives: Despite the increasing emergence of resistance, insecticide-based tools remain the primary method for malaria vector control in Africa. To maintain the effectiveness of these interventions, continuous monitoring and identification of novel resistance mechanisms is essential. This study aimed to investigate potential new insecticide resistance genes in the Anopheles gambiae complex. Methods: We analyzed whole-genome sequencing data from the An. gambiae 1000 Genomes Project. A broad range of genomic analysis techniques and tools were used to identify and explore genetic variation in the candidate resistance genes. Results: High haplotype homozygosity values, indicative of positive selection, were detected in a 2L chromosomal region corresponding to an aldehyde oxidase gene cluster (AGAP006220, AGAP006221, AGAP006224, AGAP006225, AGAP006226). Single nucleotide polymorphisms (SNPs) have been identified in these genes with frequencies up to 100%, including 569, 691, 1433, 978, and 811 non-synonymous SNPs in AGAP006220, AGAP006221, AGAP006224, AGAP006225, and AGAP006226, respectively. Copy number variations (CNVs) such as deletions and amplifications were also identified at low frequencies (<12%). Population structure analyses revealed adaptive and geographic gene flow between An. gambiae and An. coluzzii. Conclusions: This study provides evidence that aldehyde oxidase genes may contribute to insecticide resistance in An. gambiae s.l. populations. These results highlight the importance of genomic surveillance for detecting novel resistance loci and guiding the development of improved vector control strategies under changing ecological and evolutionary conditions.

The use of pesticides often leads to environmental contamination above acceptable levels. The level of contamination is related to poor pesticide application practices, in addition to the properties of pesticides and soil characteristics. The primary objective of this study was to characterize herbicides and their application practices in cereal crops in the regions of Hauts-Bassins, Sud-Ouest, Cascades, and Boucle du Mouhoun in Burkina Faso. A semi-structured questionnaire was used to collect and extract data from 617 cereal farmers in the four regions. During the survey, the identified herbicides were characterized using pesticide property databases. The survey shows that most cereal farmers in the regions are illiterate (58.18%) and have not received any training in pesticide use (84.28%). Only a small percentage of farmers (1.3%) consult technical services for the selection of herbicides to be used. The survey also revealed that 60% of farmers leave empty herbicide containers in the wild, 39.93% use water sources to clean sprayers, and 17.83% use them to prepare the spray mixture. A total of 25 active ingredients were identified in 117 commercial herbicide products with a total use of 8100 litres and 280 kg. Of the listed herbicides, 45.37% were not approved by the Sahel Pesticide Committee (CSP). Among the non-approved herbicides, 27.78% contained paraquat, atrazine, and acetochlor, which the CSP bans. The study shows that farmers do not follow good practices when using herbicides, which can contaminate different environmental compartments and cause harmful effects to non-target organisms.

Despite the increasing emergence of resistance, insecticide-based tools remain the main strategies used so far for vector control in Africa. In the absence of more effective alternatives, monitoring and screening for new resistance mechanisms remain the main strategies to ensure the continued deployment of current vector control tools. Here, we used the whole genome sequencing data from the Anopheles gambiae 1000 Genomes Project to investigate potential novel insecticide resistance genes in the Anopheles gambiae complex. We used a broad range of genomic data analysis techniques to identify and examine genetic variation in the potential new resistance genes identified. The results showed elevated Garud H12 values in the genomic regions of the 2L chromosome corresponding to the aldehyde oxidase cluster genes (AGAP006220, AGAP006221, AGAP006224, AGAP006225 and AGAP006226). The findings show a high occurrence of the two most common haplotypes in the populations, suggesting a recent selective sweep in this region driven by positive selection. In addition, single nucleotide polymorphisms (SNPs) have been identified in these genes with frequencies up to 100%, including 569, 691, 1433, 978, and 811 non-synonymous SNPs in AGAP006220, AGAP006221, AGAP006224, AGAP006225, and AGAP006226, respectively. Copy number variation (CNVs) such as deletions and amplifications were also identified in these genes at low frequencies (<12%). The analysis of population structure analysis revealed evidence of adaptive and geographic gene flow between An. gambiae and An. coluzzii, confirming the historical connectivity between both species. These findings showed the potential role of aldehyde oxidase genes in the resistance of An. gambiae s.l. populations to insecticides. This study emphasized the importance of genomic surveillance for identifying new potential genes involved in the adaptation of malaria vectors to ecological changes.

Insecticide resistance is widespread among malaria vectors in Burkina Faso. Although resistance in Anopheles coluzzii has been extensively documented, stud