Did you know that there’s a fungus in Thailand that attacks ants, invades their brains, and manipulates them to climb 25 cm up a tree and hang from a leaf on the northern side with their mandibles – perfect reproductive conditions for the fungus
Ophiocordyceps unilateralis (Ascomycota: Hypocreales) is a specialized fungal parasite that infects, manipulates and kills formicine ants, predominantly in tropical forest ecosystems. It specifically infects Camponotus leonardi of the tribe of campotini .
Worker ants are infected during foraging when the fungal spores attach to their cuticles [Hughes]. Germination and then penetration through the cuticle leads to rapid infection inside the host body . Once infected the ants will climb down from their natural habitats on rainforest tree and relocate to 25 cm off the ground under leaves where the temperature is low and humidity is high. Fungal reproduction is only possible after a stalk is grown out of the host’s head by propulsion of spores out from its fruiting bodies . Spores of O. unilateralis are actively discharged and dispersed over short distances, creating an infectious “killing field” of ∼1 m2 below the dead host (N. L. Hywel-Jones, unpublished data)
Fungal manipulation of an ant host’s mouthparts was found on a 48 million year old single leaf of the dicotyledonous plant host Byttnertiopsis daphnogenes from Messel in Northern Germany . The close modern parallel for this distinctive type of leaf damage is the death grip of some fungus-infected carpenter ants such as the fungus O. unilateralis which adaptively manipulates worker ants of C. leonardi to bite along major veins of leaves in Thai tropical forests. This is the oldest evidence of parasites manipulating the behaviour of their hosts and suggests that the specialized interaction is relatively ancient rather than newly acquired .
Due to the increased amount of research on Ophiocordyceps in recent years, the name Ophiocordyceps unilateralis is often extended to Ophiocordyceps unilateralis sensu lato to indicate that the taxonomic system for this species is currently in flux and will change as the genus and species characteristics become more defined.