Interspecific hybridization between two species is an important driver of evolution and can produce new species that are genetically and phenotypically distinct from the parents (for example, in pathogenic traits). Hybrids of human pathogenic yeasts and plant-pathogen filamentous fungi have been observed, but not human-pathogenic filamentous fungi. Now, Steenwyk, Lind et al. report the discovery of Aspergillus latus allodiploid hybrids isolated from patients with aspergillosis that were formed by the fusion of two species in the Aspergillus section Nidulantes — Aspergillus spinulosporus and an unknown, but close relative of Aspergillus quadrilineatus. Genomic analyses and studies in the invertebrate Galleria mellonella animal model revealed that the isolates exhibit heterogeneity for various pathogenic traits and are phenotypically distinct from the parental and related species.