Sunday, November 28, 2010

Ant Farmers Use Pesticide

Leaf-cutter ants- Wikipedia
Ants beat us to the discovery of pesticide use by millions of years.  A report in Livescience.com describes the association of leaf-cutter ants and the fungus crop they raise with the help of bacteria.
 
There are at least 230 species which farm fungus on leaves to eat as a primary food source.  Another fungus, called Escovopsis attacks and parasitizes the ant's fungal crop.  The ants have learned to "weed" the leaves by lapping up the spores of the invaders.

Previous studies have shown that the ants carry bacteria on their bodies.  These have been identified as Pseudonocardia, related to bacteria that have led to the discovery of antibiotic agents in the past.  What is new is a report in the Proceedings of the Royal Society which has shown that leaf cutter ants carried predominately two specific strains.
"The researchers also tested how effective different Pseudonocardia strains were in suppressing fungal growth, particularly that of the ants' nemesis Escovopsis. Here, they found that the parasite was more susceptible to the antibiotics produced by Pseudonocardia than were other fungi. They also noticed that strains of Pseudonocardia found dwelling on ants were more effective against the parasite than free-living strains." 
When ant queens take flight to set up a new colony, they carry the fungus with them, ready to start a new farming operation like we carry seeds of familiar crops.  Also like us, they may carry the parasitic fungus, an early form of an "invasive species".  

An instructive video from Science Nation demonstrates the ants at work.  Research may even lead to the discovery of new antibiotics or how leaves might be converted to biofuel.