Targeting genes involved in sexual determinism, for vector or pest control purposes, requires a better understanding of their polymorphism in natural populations in order to ensure a rapid spread of the construct. By using genomic data from An. gambiae s.l., we analyzed the genetic variation and the conservation score of the fru gene in 18 natural populations across Africa. A total of 34,339 SNPs were identified, including 3.11% non-synonymous segregating sites. Overall, the nucleotide diversity was low, and the Tajima’s D neutrality test was negative, indicating an excess of low frequency SNPs in the fru gene. The allelic frequencies of the non-synonymous SNPs were low (freq < 0.26), except for two SNPs identified at high frequencies (freq > 0.8) in the zinc-finger A and B protein domains. The conservation score was variable throughout the fru gene, with maximum values in the exonic regions compared to the intronic regions. These results showed a low genetic variation overall in the exonic regions, especially the male sex-specific exon and the BTB-exon 1 of the fru gene. These findings will facilitate the development of an effective gene drive construct targeting the fru gene that can rapidly spread without encountering resistance in wild populations.

Malaria transmission in sub-Saharan Africa is dominated by the An. gambiae complex and An. funestus group, whose distribution varies across ecological settings. Secondary species occur at lower densities, but their role in transmission may differ from one locality to another depending on local conditions. Assessing Anopheles biodiversity using ecological indices is therefore essential to characterise their diversity and relative abundance. This study investigated the biodiversity and spatial distribution of Anopheles species across the three climatic zones of Burkina Faso to guide effective vector control strategies. Indoor resting mosquitoes were collected from 67 health districts across the 13 regions of Burkina Faso between September and December 2022 using pyrethroid spray catches. A total of 30,521 Anopheles mosquitoes were identified, with An. gambiae s.l. dominating (94.4%). The Sudano-Sahelian zone recorded the highest abundance, followed by the Soudanian and Sahelian zones. Biodiversity decreased from humid southern to arid northern areas, with the Soudanian zone showing the highest diversity. Molecular analysis of 2026 An. gambiae s.l. specimens revealed marked heterogeneity: An. coluzzii predominated in Sahelian (74.9%) and Sudano-Sahelian (71.2%) zones, while An. gambiae s.s. was most frequent in the Soudanian zone (53.8%). These results highlight spatial and ecological differences in Anopheles composition across Burkina Faso and emphasize the need for locally adapted malaria vector control strategies.

The Oriental fruit fly, Bactrocera dorsalis, is a pest of significant economic interest that damages horticulture and causes major economic losses worldwide. The main control measures are based on insecticides, which are being increasingly restricted due to the development of genetic resistance. Therefore, there is a crucial need for a novel, sustainable, and environmentally safe means of controlling this pest. Advances in genome editing, aided by the discovery of CRISPR‐Cas9 tools and the development of gene drive systems, offer new alternatives for combating insect pests and vectors. Genetic suppression tools targeting key parameters could become powerful assets within the AW‐IPM programme for controlling B. dorsalis. This literature review provides an overview of currently characterized genes that could be targeted for genetic suppression of B. dorsalis.

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.

Bactrocera dorsalis Hendel is a highly invasive horticultural pest that is of major economic importance worldwide. In Burkina Faso, it is one of the main insect pests that affects the production and exportation of mangos. Understanding the biology and the genetic dynamics of this insect pest provides crucial information for the development of effective control measures. The aim of this study was to understand the distribution, diversity, and genetic structure of B. dorsalis in Burkina Faso. Male flies were collected transversally in Burkina Faso and analyzed by PCR using 10 microsatellite markers. The results showed an abundance of B. dorsalis varying from 87 to 2986 flies per trap per day at the different sampling sites. The genetic diversity was high at all sites, with an average Shannon’s Information Index (I) of 0.72 per site. The gene flow was high between study populations and ranged from 10.62 to 27.53 migrants. Bayesian admixture analysis showed no evidence of structure, while Discriminant Analysis of Principal Components identified three weakly separated clusters in the population of B. dorsalis in Burkina Faso. The results of this study could be used to optimize the effectiveness of current control interventions and to guide the implementation of new, innovative, and sustainable strategies.

1 IntroductionBactrocera dorsalis is one of the major horticultural pests of economic importance worldwide (Peng et al ., 2020; D. D. Weiet al. , 2019) and is classified as a quarantine pest in several countries (Liu et al. , 2019; CABI, 2021). This peculiar insect species has a very high invasive potential, due to a varied range of host plants and high reproductive capacity, combined with up to 100% destruction capacity of horticultural fields, which results in important ecological and economic losses in the affected countries (CABI, 2021; Ekesi et al ., 2009; Liendo et al ., 2018). Its presence in Africa was only detected about 20 years ago (Zhang et al. , 2016; CABI, 2021). However, it was able to surpass Ceratitis cosyra , the previous local fruit pest, in terms of density and damage (Ekesiet al ., 2009; Zida et al ., 2020). B. dorsalis is now the main problem within the horticultural sector in several African countries with over 40 possible host plants known to date (Zhanget al. , 2016; CABI, 2021). Chemical insecticides are currently considered the main method of controlling insect pests and vectors worldwide 2010 (Heve, Adjadeh and Billah, 2021). They were effective in eradicating B. dorsalis in parts of southern Africa such as Mauritius in 2000 and 2013 and the South African province of Limpopo in 2010. They have also reduced mango infestation in other countries such as Benin, Cameroon and Kenya (Mutamiswa et al. , 2021). However, insecticide resistance could compromise future eradication programs (Vontas et al. , 2011) as frequently shown also for other pest and vector insects such as the Mediterranean fruit fly (medfly)Ceratitis capitate (Magaña et al. , 2008), the olive flyBactrocera oleae (Pavlidi et al. , 2018), and the malaria mosquitoes Anopheles gambiae (Namountougou et al. , 2012).Recent advances in molecular biology have prompted the emergence of various genome editing tools. The development of Gene-drive technology, and more recently of the discovery and implementation of CRISPR-Cas9 tools, have revolutionized the field of insect bioengineering (Doudnaet al. , 2014; Hsu, Lander and Zhang, 2014; Oye et al. , 2014; Drury et al. , 2017) applied to the genetic control of harmful insects. Gene-drive systems, empowered by the precision, simplicity and efficiency offered by CRISPR tools, offer a promising tool for controlling insect pests and vectors (Bouyer et al ., 2018; Hammond et al ., 2016) without contributing to the increasing environmental pollution or being affected by resistance to chemical insecticides. The technology is based on the introduction of a genetic element in the insect genome (transgene) able to bias its inheritance, thereby acting as a “selfish” genetic system (Amoet al. , 2020). Deployment of this technology for pest control also has the advantage of being able to impact target populations beyond the point of release and over multiple generations (Quinn et al ., 2020) through spatial and temporal dispersion facilitated by mating reproduction (D. Amo et al ., 2020; Mudziwapasi et al ., 2021; Quinn et al ., 2020; M. J. Scott et al ., 2016; Verkuijl et al ., 2022). Gene-drive technology allows either the suppression or replacement of target populations according to the design of the genetic system introduced (Galizi et al ., 2016; Hammondet al ., 2016, 2021; Kyrou et al ., 2018; Quinn et al ., 2020). Relying on self-propagating elements, gene-drive technologies have the advantage of being easy to deploy as well as cost-effective. Promising results have already been achieved in laboratory settings where gene drives have been developed in insects such as Drosophila melanogaster (Huang, Liu and Rong, 2016; Webster, Vella and Scott, 2020), Aedes aegypti (Li et al. , 2020) and Anopheles gambiae (Hammond et al ., 2021; Kyrouet al ., 2018; Simoni et al ., 2020).The development and implementation of genetic control tools in B. dorsalis could complement existing control programs. Several genes have already been identified through studies as potential targets for this purpose (G. Liu et al ., 2015; Peng et al ., 2020; Xuet al ., 2022; J. Zhang et al ., 2018; Zheng et al ., 2018). This literature review aims to bring together relevant information and available tools to engineer effective genetic control technologies, providing an assessment of current tools and techniques available for the development of genetic control methods and gene-drives in B. dorsalis .