Ants, Fungi & Mosses

Note­wor­thy

Our re­la­tion­ships with other life forms re­sult from ex­changes that are rarely straight­for­ward. A re­cent pub­li­ca­tion that fur­ther ex­am­ines the zom­bie ant–fungus in­ter­ac­tion shows just how ad­di­tional com­plex­ity may lie at the root of some as­so­ci­a­tions. 

Re­searchers from Brazil won­dered if the fungi that in­fect ants and ma­nip­u­late their be­hav­ior could be lead­ing a dual lifestyle: as an en­do­phyte in plants and as a par­a­sitic en­to­mopathogen. In­fected ants show a pref­er­ence for spe­cific death sites, and ant-in­fect­ing species in the Ama­zon are also known to have a fi­delity to­wards bryophytes as at­tach­ment sites for death. Could this in any way be due to a co­evo­lu­tion­ary adap­ta­tion link­ing fun­gal strate­gies and mi­cro­hab­i­tats?

To test if plants con­tain en­to­mopath­o­genic fungi as­so­ci­ated with in­sect host ma­nip­u­la­tion, the sci­en­tists char­ac­ter­ized fun­gal com­mu­ni­ties as­so­ci­ated with Ama­zon­ian bryophytes. By look­ing at the highly spe­cial­ized par­a­sitic fun­gal genus Ophio­cordy­ceps, they found ev­i­dence con­sis­tent with an en­do­phytic lifestyle in Ama­zon­ian mosses.

Fig­ure leg­end Graphic schematic of the ex­per­i­men­tal sam­pling de­sign. Il­lus­tra­tive overview of the sam­pling lay­out within a trop­i­cal for­est un­der­story. Color-coded ar­rows in­di­cate sam­pling cat­e­gories: INT (bit­ten bryophyte), EXT (ad­ja­cent bryophyte, ≥ 5 cm), EPF (en­to­mopath­o­genic fun­gus), and CONTROL (bryophyte ≥ 10 m from any in­fected ca­daver). Il­lus­tra­tion pro­duced with the as­sis­tance of GenAI (Gem­ini Pro 3.1, Google); B Macro-pho­to­graph of an Ophio­cordy­ceps-in­fected ant ca­daver (EPF) bit­ing onto a bryophyte (INT). Source

The find­ings chal­lenge the pre­vail­ing idea that these fungi are strict in­sect pathogens and in­di­cate a non-ran­dom as­so­ci­a­tion that emerged over time, adding a layer of com­plex­ity that pos­si­bly con­tributes to fun­gal per­sis­tence and re­pro­duc­tion.