Researchers recently discovered a way to control cane toads, an introduced pest, in Australia: put out cat food for the meat ants, Iridomyrmex reburrus.
Sound a bit far fetched? It turns out that when scientists scattered cat food along the banks of cane toad-infested ponds, the meat ants would come to the shore to pick it up. If they encounter young cane toads emerging from the water while foraging there, the meat ants attack. In fact, in the study area 98% of emerging toads were laid into by ants within two minutes of leaving the water.
You might wonder if desirable species of toads meet the same fate. It turns out that other kinds of toads evade meat ants at all costs. Only the cane toads freeze in position long enough to for the meat ants to overwhelm them with their tough jaws.
What’s so bad about cane toads? The cane toads were introduced into Australia in an effort to control another pest in sugar cane (thus the name). Soon is became evident that when carnivorous vertebrates – marsupials, lizards, snakes or crocodiles- tried to eat a cane toad, they would succumb to its toxins. With so many cane toads, the threat to wildlife is a very real one.
Is the idea of using ants to control pests a new one? No, certain ants have been used by humans to control pests for centuries. As far as is known, the ancient Chinese were the first to use ants to protect crops. As long as 1,700 years ago, farmers employed weaver ants to keep caterpillars, stink bugs and small rodents out of their valuable citrus orchards. Today weaver ants are used to control citrus pests in Northern Australia.
The colors of this meat ant specimen photographed by April Nobile (Copyright AntWeb.org, 2000-2009. Licensing: Attribution-ShareAlike 3.0 Creative Commons License, downloaded from Wikimedia) have faded somewhat. Check out the gorgeous iridescent gaster of photographs of Iridomyrmex reburrus at Myrmecos.net.
Now, I wonder if sprinkling cat food about will keep cats from sitting on my keyboard. 🙂
Reference:
Georgia Ward-Fear, Gregory P. Brown and Richard Shine. (2010). Using a native predator (the meat ant, Iridomyrmex reburrus) to reduce the abundance of an invasive species (the cane toad, Bufo marinus) in tropical Australia
Journal of Applied Ecology, early view at journal website.