Overview
- A peer-reviewed study published October 16 in Science confirms a previously unknown, female-specific hindleg organ in the stinkbug Megymenum gracilicorne that hosts symbiotic fungi.
- The organ’s surface is a porous cuticle with thousands of openings linked to secretory cells, where fungal hyphae grow in reproductively mature females.
- During egg laying, females smear hyphae onto each egg, and lab tests showed fully fungus-covered eggs resisted parasitism, whereas cleaned or sparsely coated eggs were vulnerable; the fungi do not infect the wasps.
- Most associated fungi are in Cordycipitaceae, with notable variation among individuals and sites; fungi are transferred to eggs, lost during nymphal molts, and reacquired from the environment by adult females each generation.
- Researchers observed the organ and egg-smearing behavior across dinidorid species examined, a family of roughly 100 species found mainly in Asia and northern Africa, and field surveys recorded high baseline wasp parasitism of eggs.