Tropical trees built homes for ants. Wasps are taking them over

Predatory wasps are hijacking shelters built by tropical trees for their ant defenders, potentially disrupting an ancient partnership that protects the plants from hungry insects. The takeover is far more common in disturbed landscapes such as oil palm plantations and could have lasting consequences for forest recovery and evolution. Tropical trees built homes for ants. Wasps are taking them over.

Wasps are taking them over Date: October 5, 2026. An international team from Queen Mary University of London, the Royal Botanic Gardens, Kew, the Biology Center of the Czech Academy of Sciences, and other institutions found that predatory wasps are increasingly occupying the hollow stems of the tropical plant Macaranga pearsonii. The findings, published in PeerJ, reveal that the wasps are moving into structures that evolved specifically to shelter protective ant colonies.

For at least 10 million years, these "ant-plants" have maintained a close partnership with ants. The plants produce hollow chambers where ants can live and also supply them with nutritious food bodies. In exchange, the ants aggressively protect their host plants from leaf-eating insects such as caterpillars.