Population Genetics and Gene Flow Among Aphis craccivora (Hemiptera: Aphididae) Populations on Leguminous Crops

Abstract

Population genetics and gene flow among Aphis craccivora (Hemiptera: Aphididae) populations on leguminous crops were investigated to understand genetic structure, dispersal dynamics, and implications for pest management. Field populations were sampled from diverse legume-growing regions, and individuals were collected from multiple host plants exhibiting typical aphid infestation symptoms such as leaf curling, honeydew deposition, and sooty mold development. Genetic variation was assessed using molecular markers targeting mitochondrial and nuclear loci to evaluate population differentiation and connectivity. Results indicated moderate to high levels of genetic diversity within populations, suggesting strong adaptive potential across agroecological zones. Population structure analysis revealed partial genetic clustering associated with geographic distance and host plant distribution, indicating restricted but ongoing gene flow among regions. Evidence of migration and admixture suggested that wind-assisted dispersal and crop movement contribute to population connectivity. Some populations exhibited localized differentiation, likely driven by host specialization and agricultural practices. Gene flow patterns indicated that A. craccivora populations maintain evolutionary flexibility, enabling rapid adaptation to environmental pressures, including insecticide use and host variability. The study highlights the importance of understanding population genetic structure in forecasting pest spread and resistance evolution. These findings support the development of region-specific integrated pest management strategies and coordinated monitoring programs to effectively manage A. craccivora in leguminous cropping systems.