Iberian harvester ant queens (Messor ibericus) mate with males of a different species (Messor structor), store their sperm, and produce males that are genetic clones of M. structor while retaining M. ibericus mitochondrial DNA.
Queens produce both M. ibericus males (hairy) and M. structor-like males (nearly hairless); all colony workers are female hybrids of the two species.
Researchers coined the term “xenoparity” for this phenomenon; it challenges traditional species concepts because two distinct species are required for the M. ibericus colony’s reproductive system.
The relationship appears mutually beneficial—M. ibericus secures workers and spreads M. structor via cloned males—but cloned males may accumulate harmful mutations over time, risking long-term viability.