They are devastating in a garden but fascinating to watch in the wild. Since I live in a city I don't feel bad about trying to wipe them out of my area and save my plants. There is a pellet we can buy that they are attracted to and it appears to kill their fungus thus destroying that colony. After the rainy season the new queens go off and start new colonies though so there are intrusions at this time of year from all around my yard. I have neighbors with overgrown yards and there are a couple of unoccupied houses within my block and they establish colonies there. They seem to prefer my tender leafed garden plants over the weeds in the neighboring yards so I am fighting them off annually. The biggest problem is they can do so much damage in just one night that if you don't spot them right away they can wipe out huge areas. They even got in my pond one year and went from lily pad to lily pad taking all of the leaves from the center first. Last week they completely defoliated my large blooming bleeding heart bower vine and the week before another colony got about half of a huge jasmine before I spotted them. They are fast and they are thorough, they cut every single leaf into bits and carry it away.
Here are some links with info on them.
http://www.nsf.gov/news/specia...
http://en.wikipedia.org/wiki/L...
