Can you find a local source of Beauveria? Some species of Beauveria favorite food is ants, so those species might be best to buy. If you can't find any specific for ants, any Beauveria will do, typically. there are a couple of species of a genus that we used to call Pseudomonas that can also do this, but I haven't seen them for sale on the market for quite some time. So, Beauveria will likely be your choice.

Take some of your existing pile, start a compost tea, and add the Beauveria spores at the beginning of the brewing cycle. You could make a compost extract, add a little humic acid and the spores, and aerate for 24 hours. The spores will wake up and grow during the 24 hour brewing / aeration cycle.

Punch several pipe holes into your big pile of compost by pushing a pipe (pvc, metal, whatever) into the pile almost all the way down to the bottom, and then pull the pipe out. If you have some good bacterial and fungal growth in the pile, the hole will not collapse when you pull the pipe out. Repeat until the pile looks like you will be able to wet most of the pile when you pour the compost tea with Beauveria into those holes.

The ants may object to your disturbance of their "home", so be prepared to get the pipes in as deep as you can, and then leave for a bit. But return to finish the job once the ants settle down. Once the Beauveria is in the pile, it will take a day or two for the Beauveria to start to feast, but your pile should soon be ant-less.

Another thought, you might like to find the original ant mound and exit those ants from your life as well. The mound needs to be on your property for you to do this, but if you cut the top off the ant mound (yes, leave as soon as you do that, since the ants will be upset), and come back to pour the compost tea with the woken-up Beauveria into the mound. You want to apply enough of the organisms in the tea into the mound so the Beauveria reaches the queen's chamber. She has to die so that the colony will not come back.

I view this as a much better way to deal with the one or two ant mounds that are causing you problems. Much better than applying insecticide all over the yard and killing so much more than just the ants. Once applied, insecticides will be present, killing way more organisms than just the ants, for quite some time. Using specifically applied Beauveria to a single mound at a time kills just those ants, and leaves an area with high levels of these fungi so the ants won't come back. Very local, small area of influence, and won't be affecting your pets, your children or result in toxic run-off or leaching that could affect the water supply in your community.

Elaine R. Ingham
President, Soil Foodweb Inc. Soil Life Consultant