Mosquitoes transmit pathogens that cause human diseases such as malaria, dengue fever, chikungunya, yellow fever, Zika fever, and filariasis. Biotechnological approaches using microorganisms have a significant potential to control mosquito populations and reduce their vector competence, making them alternatives to synthetic insecticides. Ongoing research has identified many microorganisms that can be used effectively to control mosquito populations and disease transmission. However, the successful implementation of these newly proposed approaches requires a thorough understanding of the multipronged microorganism–mosquito–pathogen–environment interactions. Although much has been achieved in discovering new entomopathogenic microorganisms, antipathogen compounds, and their mechanisms of action, only a few have been turned into viable products for mosquito control. There is a discrepancy between the number of microorganisms with the potential for the development of new insecticides and/or antipathogen products and the actual available products, highlighting the need for investments in the intersection of basic research and biotechnology.

Background: The neotropical anopheline mosquito Anopheles darlingi is a major malaria vector in the Americas. Studies on mosquito-associated microbiota have shown that symbiotic bacteria play a major role in host biology. Mosquitoes acquire and transmit microorganisms over their life cycle. Specifically, the microbiota of immature forms is largely acquired from their aquatic environment. Therefore, our study aimed to describe the microbial communities associated with An. darlingi immature forms and their breeding sites in the Coari municipality, Brazilian Amazon. Methods: Larvae, pupae, and breeding water were collected in two different geographical locations. Samples were submitted for DNA extraction and high-throughput 16S rRNA gene sequencing was conducted. Microbial ecology analyses were performed to explore and compare the bacterial profiles of An. darlingi and their aquatic habitats. Results: We found lower richness and diversity in An. darlingi microbiota than in water samples, which suggests that larvae are colonized by a subset of the bacterial community present in their breeding sites. Moreover, the bacterial community composition of the immature mosquitoes and their breeding water differed according to their collection sites, i.e., the microbiota associated with An. darlingi reflected that in the aquatic habitats where they developed. The three most abundant bacterial classes across the An. darlingi samples were Betaproteobacteria, Clostridia, and Gammaproteobacteria, while across the water samples they were Gammaproteobacteria, Bacilli, and Alphaproteobacteria. Conclusions: Our findings reinforce the current evidence that the environment strongly shapes the composition and diversity of mosquito microbiota. A better understanding of mosquito–microbe interactions will contribute to identifying microbial candidates impacting host fitness and disease transmission. Graphical

Malaria continues to affect millions of people around the world. Current control strategies have not been sufficient, and additional tools are required for malaria elimination. A promising approach is the use of bacteria from the mosquito microbiota, such as the Su_YN1 Serratia ureilytica bacterium, which is shown to strongly impair the development of P. falciparum and P. berghei in Anopheles mosquitoes. To evaluate the potential of using S. ureilytica Su_YN1 to block the Plasmodium parasite in South American vectors, we investigated its effects on mosquito fitness and survival. We found that this bacterium does not affect the longevity, blood feeding, fecundity and fertility of Anopheles aquasalis, an important South American vector. Overall, our results provide baseline support for the potential implementation of Su_YN1 for the control of malaria transmission in South America.

Climate change is expected to alter the ecology, persistence, and geographic distribution of mosquito vectors, yet the molecular traits underlying vector responses to future environmental conditions remain insufficiently understood. Aedes aegypti, a major vector of arboviruses, depends on tightly regulated reproductive and lipid-transfer pathways that are linked to population replacement and persistence. Here, we experimentally evaluated whether projected late-century increases in temperature and atmospheric CO₂ affect the transcriptional regulation of lipophorin- and vitellogenin-associated genes in female Ae. aegypti. Mosquitoes were reared under controlled IPCC-based climate scenarios simulating current, mild, intermediate, and extreme future conditions, and the relative transcription of LpII, LpIII, LpR, VgA1, VgB, VgC, and VgR was quantified by RT-qPCR. Increasing environmental severity was associated with a progressive reduction in the transcription of genes involved in lipid transport, yolk precursor production, and receptor-mediated nutrient uptake. Vitellogenin-associated genes showed stronger transcriptional sensitivity than lipophorin genes, particularly after blood feeding, and receptor downregulation under extreme conditions was consistent with altered molecular pathways involved in ovarian nutrient acquisition. Regression and correlation analyses further indicated negative relationships between simulated temperature increase and transcriptional levels of key reproductive genes. These findings identify reproductive lipid metabolism as a climate-sensitive molecular trait in Ae. aegypti and suggest that future warming and elevated CO₂ may affect molecular pathways linked to reproductive investment, a possibility that requires functional validation. This study contributes to understanding how environmental change may shape molecular responses in disease vectors under future climate scenarios.

Mosquitoes transmit pathogens that cause human diseases such as malaria, Dengue fever, Chikungunya, yellow fever, Zika fever, and filariasis. Chemical pesticides are effective instruments for reducing disease transmission and managing mosquito populations. However, these chemicals have drawbacks such as high production costs and negative effects on the environment and non-target organisms. Furthermore, as mosquitoes develop resistance to chemical insecticides, they become less effective. As a result, researchers are investigating novel insecticides. Advances in microbial biotechnology have resulted in a wide range of value-added products, including biopesticides for agricultural and public health purposes. In this review, we highlight the mainly untapped biotechnological potential of microorganisms for vector mosquito control and disease transmission reduction. Also, we underline the importance of more basic research and improved translational research methodologies, encouraging efforts to bridge the gap between academic research on biopesticides and public health interventions.

Malaria continues to affect millions of people around the world. Current control strategies have not been sufficient, and additional tools are required for malaria elimination. A promising approach is the use of bacteria from the mosquito microbiota, such as the Su_YN1 Serratia ureilytica bacterium, that was shown to strongly impair development of P. falciparum and P. berghei in Anopheles mosquitoes. To evaluate the potential of the S. ureilytica Su_YN1 bacterium as a blocker of the Plasmodium parasite in South American vectors, we investigated its effects on mosquito fitness and survival. We found that this bacterium does not affect longevity, blood feeding, fecundity and fertility of Anopheles aquasalis, an important South American vector. Overall, our results provide baseline support for the potential implementation of Su_YN1 for the control malaria transmission in South America.