Posts Tagged ‘leaf cutting ants’

Stopping Leaf Cutting Ants

Monday, March 11th, 2013

Last month I noticed that a two foot section of sugar snap peas had been cut down almost to the ground.  I inspected the damage expecting to see evidence of squirrels or some other mammal, but instead discovered that my arch-nemesis, the leaf cutting ant, had returned.  I saw them methodically carrying away pieces of pea leaves, bigger than their own bodies.

I have a leaf cutting ant nest somewhere on my property, probably underneath my front porch.  I can’t determine the exact location of the nest because their tunnels can extend a hundred feet or more.  I’ve written about the ants before here, and have mostly learned to live with them.  They remain dormant most of the time, but make appearances several times a year.   Each time that they emerge they choose one type of plant to eat, ignoring the other vegetation.  This time it was peas.

Pea stalks chewed off about four inches high.

Peas plants damaged by leaf cutting ants.

Because the ants don’t actually eat the leaves, but instead use them to grow fungus, most insect controls don’t work on them.  For example, both Noel and I have had excellent results spraying neem oil on our plants to control leaf eating insects.  But for the neem to be effective, the insects must ingest it.  This doesn’t happen with the ants.

Luckily this time I noticed the ant outbreak before they had destroyed all of the peas.  I found that they had only tunneled into the pea bed in one location.  I poured orange oil into the hole.  I returned to the bed two days later and did not see any further damage.  I did, however, find about a dozen ants wandering around the bed still carrying now shriveled pieces of leaf.  Apparently I had severed their only connection with the mother colony.

Small hole in soil.

Leaf cutting ant tunnel entrance.

I won one round in my struggle with the ants.  But I know that they will be back.  And from past experience, I also know that they usually get what they want.