Solutions for Ant Problems

Editors Note: Many thanks to Jami, who wrote this post in response to an ant problem that is plaguing each and every one of my plants on my lanai (balcony) in Honolulu. There is so much good information here- I hope you find it as useful as I did! aloha, ADB

You were sad that summer was over, yet happy to have the greenery back inside to brighten the grey days of winter. Or maybe you live in an area where you can grow beautiful potted plants all year long. But whether your potted plants are inside or out, on a balcony or patio, at some point you will likely find a trail of ants coming and going from the pot. This seems like a simple yet frustrating problem, yet depending upon where you live, it could be one of deep frustration.

Perhaps what you have is a simple native ant problem. Yet if you live in a warm climate, it could be fire ants, or Little Fire Ants (LFA) that are infesting your pots if you live in Hawaii. Of course you would notice this as you bring a pot inside, so it is easier to prevent this problem before it becomes… well, a bigger problem. Although native ants can cause frustration, it is the fire ants located in the southern United States and the Little Fire Ant in certain areas of Hawaii, that are the most problematic. All of the solutions for ant problems use natural or organic products. Except for the Little Fire Ant. You will learn the reasons why later in the article.

NATIVE ANTS

For native ant infestations, first look to see if you have aphids or scale on the plant. These are both insects that suck the sap from your beautiful plants then produce honeydew that draws the ants. I get scale on my citrus trees every year without fail if I place them outside. The first thing I make sure to do is ensure the plant is getting enough water (but not too much), has enough nutrition, and then remove the insects. After removing any sap sucking insects, you may follow these recommendations:

  1. Submerge the pot in water just above the soil line for half an hour.  This can be done in a bath tub, a bucket or an outdoor tub just a bit larger than your pot. Another option is to submerge in a solution of water and insecticidal soap and water for 20 minutes.
  2. Diatomaceous earth (DE) can be sprinkled on the top of the soil, and if outside, around your pots and on the ground and grass. This type of control is effective at killing most insects, so be careful in it’s use as you could kill as many or more beneficial insects as those causing you problems. Since this dust is composed of tiny sharp particles, it is best to use a dust mask during application. Horticultural DE can be purchased at local plant nurseries or box stores that sell plant supplies.
  3. Baiting is an effective, yet slower method of ant colony removal. If the queen does not die, ants will again appear. Commercial baits are the best choice, with the placement of the baits on either side of the colony’s trail rather than on it. Check regularly to ensure the bait has food in it until you see no ants coming and going.

FIRE ANTS

I remember well the first time I was stung by fire ants. Being naïve I thought the bite was just that, a little bite. Was I wrong! The numerous bites stung for more than a day, much like a sting from a yellow jacket. Fire ants were accidentally imported from Brazil to Mobile, Alabama in the 1930s. Their spread has happened more quickly than in their native land because of the lack of predatory insects. Fire ants are found from North Carolina to Northern Florida then west to California. Being omnivorous, this variety of fire ant feeds on insects, animals, plants, seeds, seedlings, buds and developing fruit. They have had a devastating affect on native ecosystems, having a two-fold decrease in populations as diverse as insects to birds to mammals.

It is important to be sure to kill the queen ant located deep in the underground hive, as she is capable of producing up to 1,600 eggs per day. Fire ants often repopulate after a rain, so be aware of this if you use the submersion method noted above. It has been reported that insecticides have served to wipe out competing and predatory insects, thus leading to an even greater population growth of the imported fire ant. The best biological control for the fire ant population at this time is the native ant, because it is a direct competitor for limited food resources.

Solutions for fire ant control:

  1. Use boiling water, up to 3 gallons on large mounds
  2. Drenching the mound with one of four organically approved mound drenches that have one of these active ingredients: D-limonene or spinosad.
  3. Baits that contain spinosad, putting them in place in the early evening when the ground is dry by placing it on the mound spreading to 2 feet around it.
  4. Diatomaceous earth can be applied alongside with other natural products, including those containing pyrethin, to enhance the effectiveness of each. If ants are found inside, apply DE to their trails.

A promising and less toxic solution to ant problems is called the Texas Two Step, developed in Texas through the cooperation of various agencies and universities. Here is the two step process:

  1. Bait.  apply a product whose active ingredient is spinosad, making sure all is dry and will be dew rain freed for a number of days, applying directly onto mounds.
  2. Mound treatment. This could be boiling water or a mound treatment product.

LITTLE FIRE ANTS

In recent years Hawaii as seen the influx of a number of species from other locations, including the Little Fire Ant. It was accidentally introduced from Central and South America, possibly being transported in potted plants to the eastern part of the state in the 1990s, although they are now creating problems in the western part of the state. These insects are tiny, being only about 1/16th of an inch in size and red-orange in color.

The native “red ant” is also a stinging ant, although does not have the devastating effects of the LFA, causing animals to go blind if they have multiple stings to the eyes clouding the cornea.  Death can be a result should an allergic reaction develop. The stings of these little insects pack quite a punch with a strong burning that lasts for weeks.  This little ant is not territorial, so colonies will build and grow stronger, out-competing native species. They thrive in moist shady areas.  Effective controls are still being developed. The active ingredient Tango is a pesticide that contains methoprene. Although this control is not organic, it is one of the few that is showing effectiveness in controlling LFA populations and is approved for use around food crops. Results will be seen in 2-3 months and applied every four to six weeks for a year.

Resources:

http://westhawaiitoday.com/sections/news/local-news/fire-ants-little-pest-big-problem-invading-isle.html
http://growingsmallfarms.ces.ncsu.edu/growingsmallfarms-fireants/
http://www.hawaiihealthguide.com/healthtalk/display.htm?id=613
http://www.vegetablegardener.com/item/8107/diatomaceous-earth-as-non-toxic-ant-killer
http://fireant.tamu.edu/?s=natural+fire+ant+killer

 

Ant and leaf image from Shutterstock

About the Author