Editorial: Unravelling Insect Vector Diversity: Genetic and Phenotypic Insights from the Global South

Romina Valeria Piccinali^1*Ana Laura Carbajal-de-la-Fuente^2*Julieta Nattero¹Sebastián Pita³Carlos Eduardo Almeida⁴

• ¹Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
• ²Centro Nacional de Diagnóstico e Investigación en Endemo-Epidemias (CeNDIE), Administración Nacional de Laboratorios e Institutos de Salud “Dr. Carlos Malbrán” (ANLIS), Ciudad Autónoma de Buenos Aires, Argentina
• ³Universidad de la Republica Uruguay, Montevideo, Uruguay
• ⁴Laboratório Nacional e Internacional de Referência em Taxonomia de Triatomíneos, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brasil, Rio de Janeiro, Brazil

The concept of the Global South emerged to promote collaboration among countries, mainly in the Southern Hemisphere, on political, economic, environmental, technical, and health issues (1). Among its most persistent health challenges are vector-borne diseases, whose dynamics are closely linked to the ecology, genetics, evolution, and diversity of their insect vectors (2)(3)(4). Many insect species function as biological and mechanical vectors, transmitting viruses, parasites and bacteria (5), and can even act as parasites themselves (6). Despite extensive control efforts targeting dengue, malaria, Zika and Chagas disease, among others, these infections continue to impose a considerable burden on public health systems and local communities (7)(8).The remarkable environmental heterogeneity and high transmission rates make the Global South a key region for exploring relationships between genetic variation, phenotypic adaptation, and disease ecology. Strengthening our understanding of the genetic and phenotypic variability of vectors -such as mosquitoes, triatomines and flies -is essential to elucidate how these traits influence transmission patterns. This knowledge is particularly relevant in a world where climate change ( 9) urbanization (10), landscape transformations (11), and political or sanitary instability continuously challenge the implementation and sustainability of integrated vector control strategies (12). A complementary molecular approach is offered by Alqurashi et al., who analyzed Ae. aegypti populations from the urban centers of Jeddah and Jizan, Saudi Arabia. Using mitochondrial COI barcoding, they revealed substantial genetic divergence between the two populations, emphasizing the complex population structure of this key vector. The Jeddah population was genetically closer to those from Argentina and Australia, suggesting a shared ancestry or introduction route, while Jazan showed greater genetic diversity and affinities with mosquitoes from multiple regions, indicating a more diverse origin or higher gene flow. These results underscore the global connectivity of vector lineages and the importance of molecular surveillance in understanding invasion routes and potential gene flow across continents. While molecular studies dissect genetic and endosymbiont diversity, a second group of contributions focuses on phenotypic variation and environmental adaptation, particularly in triatomine bugs-vectors of Trypanosoma cruzi, the euglenozoan responsible for Chagas disease. These papers illustrate how environmental pressures such as urbanization, habitat fragmentation and geographic gradients shape the morphology, dispersal potential, and ultimately, epidemiological relevance of vector populations. Fiad et al. investigated the effects of habitat fragmentation over flight-related traits in Triatoma garciabesi and T. guasayana. Using geometric morphometrics and landscape metrics, they found species-specific morphological responses to fragmentation. T. garciabesi displayed increased head asymmetry and narrower wings, while T. guasayana showed subtler shape changes and stronger sexual dimorphism.The findings highlight how anthropogenic landscape modification can act as a selective force on dispersal-related traits.Urbanization represents another axis of environmental pressure, explored by Piccinali et al., who analyzed morphological variation in T. infestans populations from urban and rural areas of San Juan, Argentina. Their results showed consistent size reductions in urban populations, accompanied by shape modifications in wings and pronota. These patterns align with the "simplification hypothesis," positing that urban environments select for smaller, less complex morphologies. The study underscores how cities are reshaping vector evolution, demanding tailored surveillance and control strategies for urban Not only a vector-borne disease hotspot, but also a source of knowledge and resilienceThe collective message emerging from this Research Topic is clear: the Global South is not merely a region affected by vector-borne diseases-it is also a source of research and discovery in vector biology.By combining nucleic acid quantification, DNA barcoding, morphometric analyses, and ecological information, the studies presented here highlight the ability of Global South countries to generate high-quality science that, adjusted to local challenges, adds a unique and valuable perspective to global research. Future challenges will require sustaining and expanding this integrative vision. As climate change, urban expansion, and globalization continue to reshape vector biology, collaborative research combining genetic, ecological, and evolutionary approaches will be essential to anticipate and mitigate disease emergence. Building stronger bridges between science, decision-makers, and affected communities will be essential. Such connections will enable responses not only technically sound but also socially and culturally grounded, fostering more equitable and effective strategies to anticipate and mitigate disease emergence.