Multiple drivers synergistically shape the genetic differentiation pattern and invasion potential of Bactrocera...

As an oligophagous pest of Artocarpus fruits, especially breadfruit and jackfruit, Bactrocera umbrosa poses a growing threat to global agriculture through trade-facilitated invasion. This study integrates population genetic analysis (321 COI sequences) and ecological niche modeling to elucidate its population structure, historical dynamics, and invasion potential.

Genetic analyses revealed three phylogeographic groups: genetically diverse Southwest Pacific (SWP), Mainland Southeast Asia (MSEA), and Island Southeast Asia (ISEA). Subregional differentiation in Southeast Asia was likely driven by geographical barriers (e.g., the Isthmus of Kra) and human activities. Neutrality tests and mismatch distributions indicated recent demographic expansions across all populations, most pronounced in MSEA. Ecological niche analyses showed SWP populations with broad climatic tolerance, while MSEA and ISEA exhibited niche contractions, reflecting environmental filtering or founder effects during colonization. Projections under the SSP1-2.6 and SSP5-8.5 climate scenarios suggested range expansion to tropical Africa, the Amazon Basin, and Southeast Asia by the 2030s and 2050s. Notably, the potential geographical distribution of this pest significantly overlapped with suitable cultivation zones of Artocarpus altilis and Artocarpus heterophyllus. Regions such as the Caribbean, West Africa, and South Asia were identified as areas facing a heightened invasion risk.

This study highlights synergistic roles of geographic factors, human activity, and climate change in shaping population genetic structure and invasion potential of B. umbrosa. These insights can facilitate preemptive management of this pest under accelerating globalization and climate change. © 2025 Society of Chemical Industry.