UF/IFAS Okeechobee County Extension Service

458 Highway 98 North

Okeechobee, FL 34972-2578

Phone: (863) 763-6469

E- mail:  dfculbert@ifas.ufl.edu

July 26, 2007

Feature Article - for release the week of  July 29, 2007

Dan Culbert - Extension Horticulture Agent 

 Crazy Ants in our plants

County Extension Director Pat Miller recently called me while I was on vacation.  He’s good about helping folks practice a balance between work and family, so I was a bit concerned when he reported that a lady had called desperate for help, and he wasn’t sure what was going on.

The caller claimed that her entire yard was crawling with ants -- millions of them.  They had invaded her place about a year ago, and had driven off all the imported fire ants and “bull ants”.  And nothing that she had tried seemed to be working.  (I said to myself, no way those numbers are right - and to drive off fire ants?  Right….)

Mr. Miller drove Livestock Agent Pat Hogue, our FYN Program Assistant Angela and I to the home near the Okeechobee Civic Center.  And sure enough, the homeowner was right - here were ants EVERYWHERE!

This peaceful yard in Okeechobee is anything but: millions of ants are crawling all over the turf, the trees and the patios.  Photo: Dan Culbert, UF/IFAS

Cleaning up large piles of dead ants are a daily cleanup chore for this homeowner after she sprays them with pesticides. Photo: Dan Culbert, UF/IFAS

 

The Earth was moving

Click on the ant above to see movies of this ant made by Texas A&M entomologists. (Then move down the page to "Biology" section.)

I had never seen a massive infestation of ants like this in the US, although I saw something close to it in Costa Rica last spring.   There were trails leading everywhere: across the lawn, under potted plants, up into laurel oaks, along side the house foundation, under building slabs and even up into the rafters of the pole barns.   

Ants were moving very quickly along trails.  Standing still in any spot on the property, if you looked carefully, you would soon see the ants moving along the ground. In some cases the workers were carrying the whitish pupa from one place to another.  Their movement was not the random motion that is seen with typical crazy ants. 

 

These creatures are golden to reddish brown in color and are about the size of the typical fire ant. If they are disturbed, they may bite, but it’s a pinch – they do not sting.   After feeding on sweet sugar water, the ant's rear portion of the abdomen will appear to be striped because it is stretched out and full of food.  (I didn’t know that ants could have beer bellies!) 

The homeowner had established a daily routine of ants spraying around porches and the perimeter of the house every day.  The result was massive piles of dead ants along the nooks and crannies outside her home.  These piles would need sweeping from sidewalks and patios.  Calking and replacing the weather-stripping around doors and windows seemed to help keep them out of the house.

 

We asked the homeowner when this problem seemed to have started.  She recalled that it had been about a year.  This was about the same time that a nearby construction project was started.  She reported that the neighboring yard was also seriously infested. 

 

After we left her property, we drove down the street to the old Okeechobee Civic Center, and inspected that building and its grounds.  It was also crawling with similar huge numbers of ants in the same kinds of places that were infested in our caller’s property. The day camp program there was also under attack by these creatures

 

ID is Key to Management

We scooped up several samples of this mystery menace.  They were put into alcohol for delivery to the UF/IFAS Insect Identification Lab in Gainesville the following day.  I showed the sample to Dr. Phil Koehler and his associates, and described its behaviours and history. A peek at the ant’s anatomy and a comparison with some of the colonies they maintain there at the Department of Entomology, and we had our answer.

 

The Caribbean Crazy Ant is the proposed common name for Paratrechina pubens, a non-native ant that has been seen in the Miami area for 50 years.  Recent colonies in the port of Palm Beach have appeared to have spread into Martin and St. Lucie counties.  A question that we can not answer is if construction equipment from the coast brought some soil residues with some of these ants to Okeechobee.

 

What makes this ant so prolific is that their colonies have several hundred thousand individuals.  They appear to nest in several locations (called polydomous) and have multiple queens (called polygamous).  These ants create one big ant society, and drive off any and all others.  So that explains why the homeowner has not seen fire or bull ants for the past year - but it’s still not a desirable way to get rid of those pesky fire ants!

 

Management options

We do not have any magic silver bullets to use against the Caribbean Crazy Ant. Until more research is done we recommend the use of contact residual insecticides sprayed along active trails and nest sites to reduce ant populations, followed a few days later by sweet ant baits placed at numerous locations along trails and frequently replaced with fresh bait.  Dr. Koehler suggests the use of granular insecticide baits labeled for general landscape use with the active ingredient fipronil [e.g. Over 'n Out Fire Ant Killer Granules] or cyfluthrin [many products have this ingredient]. 

Up near but still outside the house, products with cyfluthrin, bifenthrin, or permethrin may give you relief from invasions of these Crazies.  Be careful not to use products designed for outdoor use in indoor locations – it’s just not safe to do so.  And as with the use of any pesticide, read and follow all label directions first. So remember, even when you are desperately seeking relief from such pesky critters, THE LABEL IS THE LAW.

A more complete list of recommended Ant insecticides  is available from our office.  UF/IFAS has a bulletin on Caribbean Crazy Ant – we can provide you with one if you contact us.  And I’ve placed more information on our Okeechobee web page, http://okeechobee.ifas.ufl.edu.  If you need additional information on the Caribbean Crazy Ant, please email us at okeechobee@ifas.ufl.edu or call us at 863-763-6469.  Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our Okeechobee County Master Gardeners from 1 to 3 PM on Tuesday afternoons. GO GATORS!