Scientists at Pennsylvania State University in the United States have discovered the mechanism of infection of ants by the fungus Ophiocordyceps unatellis, which turns insects into a kind of zombie. It turned out that the pathogen does not invade the brains of arthropods, but affects the jaws. This is reported by Science News.
The researchers analyzed the striated jaw muscles of infected carpenter ants using scanning electron microscopy. In dead insects, muscle fibers are destroyed, but the fungi do not affect the nerves that control the muscles. As a result, the jaws are closed in a death grip, which allows insects to gain a foothold on the upper parts of the plants.
Scientists also noticed that the infected fibers contain tiny particles that resemble bunches of grapes. These formations can be extracellular vesicles containing various molecules, which are produced either by the host or by the parasite itself. They can play a signaling role by participating in the capture of the body of insects or being the response of cells to infection.
Cordyceps infested ants leave their nests, climb plants such as Spanish moss or pine, and die. From their head, the fruiting body of the fungus grows, which spreads its spores over long distances, capturing the nervous system of new insects.