Ambrosia beetle invasions are structured by inbreeding, intraspecific hybridization, and bridgeheads.

Invasive Euwallacea fornicatus populations show minimal nuclear variation but hybridization events, revealing complex invasion dynamics and hybrid origins across continents.

• Why it matters: Understanding how inbreeding and hybridization influence invasive species is crucial for managing biosecurity risks and predicting invasion success, especially for species threatening global ecosystems.
• What they did: Genomic analysis of 247 samples from native and invasive regions identified a single, genetically uniform invasive lineage with hybridization events, heteroplasmy, and reduced deleterious mutations in native populations.
• The result: Findings suggest outbreeding can mitigate genetic load in invasive populations, emphasizing the role of gene flow in invasion success and the importance of biosecurity measures to prevent further hybridization.