Where have all the native Ants gone???
Location: Mount Washington, Los Angeles, California
January 8, 2014
When we first moved to Mount Washington in 1995, we had not yet begun writing What’s That Bug? and we lived in a rental home several hundred feet away from our current offices. Across the street were several vacant lots (two houses were recently built on the site) and there was a sunny south-facing slope. We frequently saw large, red Harvester Ants in the street, but it has been at least fifteen years since we have seen any native ants in the neighborhood. We were reminded of this because of this posting from the Natural History Museum of Los Angeles County blog regarding the North Campus urban garden. We wondered why Lila and Leslie had to travel 1000 miles to bring back what should be native ants, so we called Julian Donahue, who despite living on Mount Washington for many decades, has never seen native Ants here. Though we do not promote extermination on What’s That Bug?, if we had the opportunity to eradicate anything in our grounds, it would be the invasive Argentine Ant, a species we have battled wherever we have lived in Los Angeles in the past 34 years. We believe the Argentine Ant is responsible for crowding out native Harvester Ants in our immediate neighborhood and quite possibly in all of urban Los Angeles. Julian also mentioned that we no longer have Horned Lizards locally because they feed on the Harvester Ants. See California Herps for photos of Horned Lizards. If you live in Los Angeles, and you have native Harvester Ants, please let us know. If you know how to control Argentine Ants, please let us know.
Ed. Note: We wrote to Lila Higgins and Richard Smart at the Natural History Museum to get their opinion on this matter. Here is what Richard wrote back.
Hey Daniel,
Lila and I visited a property last July in Tujunga, and there were harvester ants on this homeowners property. It appeared to be a healthy colony, but it should be noted that this homeowner had worked really hard to turn his property in a native habitat.
I then checked out the website iNaturalist (which hosts some of our citizen science projects), and found a lot of Harvester Ants (Genus Pogonomyrmex) observations in California. Here is a link to a map of the Harvester Ant observations. You can click on the individual place markers to see the observations, and you can zoom in and pan around the map to focus in on the Greater L.A. Area.
Lila is traveling to San Diego today for work, so her response may be delayed.
Sincerely,
-Richard
Sadly, harvester ants and horned lizards are in decline in Texas also. I once saw mourning doves “anting”, placing harvester ants under the feathers on their wings. Apparently the harvester ants eat the birds’ lice. Amazing symbiosis!
The last harvester ant city I have seen was at the edge of the sand dunes at Port Aransas, Texas, in Dec 2013. It was great to see a healthy community of harvesters.
I read that the invasive fire ants may be the culprit for harvester ant decline in Texas.
Fire ants are dangerous because they swarm and inflict many stings when disturbed. I confess to using a commercial ant bait that the workers carry to the queen; we sprinkle the granules on the fire ant mound, and the ants are gone within a few days. Sometimes a second or third mound pop up nearby and we repeat the process.
I normally dislike using chemicals on the lawn or garden, but fire ants are dangerous, so I make an exception for them.
Good luck in your battle with your invasive ants.
Thanks for your information Ellen. Even though we do not promote extermination, sometimes drastic measures are required for invasive species.
Sadly, harvester ants and horned lizards are in decline in Texas also. I once saw mourning doves “anting”, placing harvester ants under the feathers on their wings. Apparently the harvester ants eat the birds’ lice. Amazing symbiosis!
The last harvester ant city I have seen was at the edge of the sand dunes at Port Aransas, Texas, in Dec 2013. It was great to see a healthy community of harvesters.
I read that the invasive fire ants may be the culprit for harvester ant decline in Texas.
Fire ants are dangerous because they swarm and inflict many stings when disturbed. I confess to using a commercial ant bait that the workers carry to the queen; we sprinkle the granules on the fire ant mound, and the ants are gone within a few days. Sometimes a second or third mound pop up nearby and we repeat the process.
I normally dislike using chemicals on the lawn or garden, but fire ants are dangerous, so I make an exception for them.
Good luck in your battle with your invasive ants.
Curious now, I looked up “anting”, and resources vary in the explanation for this widespread bird behavior, but many ornithologists believe that the birds pick up ants for the formic acid release, which acts as bug/mite repellent. A few believe the ants eat mites, which is what I had read in my bird guide. Birds are fascinating.
Here is a link to a conference on ants to be held in Palm Springs, CA in 2014. Do you need a few days in Palm Springs to study ants? 🙂 I think it sounds so cool:
http://www.extension.org/pages/19257/imported-fire-ant-and-invasive-pest-ant-conference#.UtDosfRDuSo
Hi Ellen,
We will have to check our calendar to see if we can get away.
Curious now, I looked up “anting”, and resources vary in the explanation for this widespread bird behavior, but many ornithologists believe that the birds pick up ants for the formic acid release, which acts as bug/mite repellent. A few believe the ants eat mites, which is what I had read in my bird guide. Birds are fascinating.
Here is a link to a conference on ants to be held in Palm Springs, CA in 2014. Do you need a few days in Palm Springs to study ants? 🙂 I think it sounds so cool:
http://www.extension.org/pages/19257/imported-fire-ant-and-invasive-pest-ant-conference#.UtDosfRDuSo
Somewhere along the trails of Lake Balboa Park I have once stumbled upon a nest of harvester ants. Not only at that particular spot but also at another park across the street. Is it me or I am having a feeling they are slowly reemerging? I have photos if anyone is interested.