There are many types of fungus that will invade insects in order to reproduce, but most kill the host and then release spores. Two new species of fungus discovered in Denmark consume their fly hosts from the inside out, but keep them alive for as long as possible to walk or fly around while the fungus shoots spores out of the fly's abdomen over a larger area than they could from a deceased fly, which also brings them into contact with new victims. A study from the University of Copenhagen identifies these new fungi as Strongwellsea tigrinae and Strongwellsea acerosa.
The unusual tactic of keeping the host alive while releasing spores is called active host transmission (AHT). It is an effective way of getting access to other healthy individuals. Scientists think the fungi could be producing substances that "dope" their hosts (sometimes colloquially referred to as "zombies"), meaning they can stay fresh enough to live for days after infection – only collapsing once there is nothing left in their abdomens but the fungus.
"We suspect therefore that these fungi may produce amphetamine-like substances which keep a fly's energy levels high up until the end," said lead researcher Prof Jørgen Eilenberg from the department of plant and environmental Sciences at the University of Copenhagen. Researchers also believe the fungi produce substances that keep microorganisms away from the fly fungal wound and keep it clean, but they are yet to test this.
[via Damn Interesting]