Semi-natural habitats adjacent to sorghum affect arthropod biodiversity within sorghum fields: Management implications for Melanaphis sorghi across sorghum growth stages

Increases in agricultural production have modified the landscape and affected pest management. Landscape modifications create sharp edges with semi-natural habitats and crops (i.e., ecotones) that may affect arthropod biodiversity over time. High levels of arthropod biodiversity are a valuable asset to agroecosystems as diverse populations of arthropods can provide ecosystem services, such as pest management. Our aim is to increase understanding of how ecotones influence arthropod biodiversity and pest management in agroecosystems as the crop matures. We assessed Texas sorghum fields bordering sorghum (control), cotton, and semi-natural habitat (primarily rangeland/grassland) during a three-year period from 2023-2025, sampled arthropods across the ecotone, and monitored populations of Melanaphis sorghi (Sorghum aphid) in sorghum. Specimens were identified to family-level taxa with select species identification, such as M. sorghi and principal natural enemies, and multivariate analyses were used to measure differences in arthropod biodiversity and population abundance across multiple vulnerable sorghum life stages. Our findings reveal that sorghum fields exhibit significant differences in arthropod biodiversity. Specifically, sorghum fields adjacent to semi-natural habitats had higher levels of biodiversity than those next to cotton and sorghum. Additionally, there was no correlation between the populations of M. sorghi and their natural enemies and the adjacent habitat. Across three years, semi-natural habitat next to sorghum supported higher arthropod biodiversity in sorghum fields, but there was no observed benefit for M. sorghi pest suppression.