Argentina Ants Case Studies – PCT



Adult Argentine ant (Linepithema humiliates)

Pest and Disease Image Library,

Argentinian ants (Linepithema humiliates) are, in my experience, the most problematic pest ant species in the Carolinas. (And I know a lot of other areas too!) They may not be on the level of insanity like wild wild ants (Nylanderia fulva), but they are very close. Every year, from the start of spring, these ants come out of their hiding places, multiply and spread across the landscape like a virus. These tiny brown six-legged alien invaders are proliferating and conquering the urban environment.

We think we are ready for them. At the same time, we come out fresh from our state association conferences and training sessions, armed with new knowledge and better products ready to go to war. With experience, we begin to find their weaknesses. We find products and application techniques that give us the upper hand. We can ward off infestations and wipe out their populations. We have the impression of winning. But alas, it’s a never-ending war. I inevitably get this phone call from a technician who has been defeated and needs my help.

Argentinian ants are everywhere in the Carolinas, where the Terminix service provides ant control.

K. Hathorne

ANTS AT THE LAKE. There are beautiful lakes in the Carolinas and a large number of problematic calls are from residences located around these areas. Argentines love humidity and living on a lake sets them up pretty well. Last summer I visited one such account – a stately home on a beautiful property located at the end of a deep-water peninsula. Hundreds of feet of shoreline wrap around three sides of the heavily wooded land bordered by rip-rap boulders. It was a paradise for Argentinian ants. (I’m sure that would be Heaven for a lot of people too!)

The property has seen an invasion of epic proportions. Ants were hanging out everywhere. All along the rocks along the shore, multiple trails on every tree on the property and anything on the ground served as a nesting site. I could turn just about any bunch of pine straw or piece of landscaping material, put my hand on the ground, and immediately cover it with hundreds of scurrying ants. I had seen similar videos of people dealing with wild wild ants.

While there were a lot of ants crawling outside the house, luckily the interior was relatively free of foraging ants. The service technician had done a great job keeping them out of the house, but knew it was only a matter of time before they conquered this space as well, and the owners were getting nervous. As for how these things usually go, I educated myself on the products and techniques used. I asked if any baits were being used on this account, and the tech said yes, but he couldn’t fill them up fast enough, didn’t make much difference and cost the branch a lot of money. He pointed to the rocks along the shore and said, “Ants live under all these rocks and look how much shore there is on this property. The number of stations and bait needed would cost a small fortune. I could see his point.

We thought about it and came up with a plan. This included extending the treatment area further from the house with an imidacloprid product and moving the ant bait stations to the base of trees near the house. I upgraded it from gel ant bait to liquid ant bait to help keep costs down. We explained to the client that the cost would prevent us from eliminating ants along the coastline, but adjusting our treatment could impact populations close to the house; they were okay with it. A few weeks later, I found out what we were doing was working. There were still a lot of ants on the property but they stayed away from the house and the client was happy with the outcome.

K. Hathorne

Ants in rip-rap rocks around a lake property.

DUTY OF THE DISHES. So while we were feeling pretty good about our win, another tech in a different field had a problem with the Argentinian ants. After clearing out all other settlements on the property, the little buggers continued to appear inside the customer’s dishwasher. The client has not seen ants hanging out inside since the first treatments, but when she opened the dishwasher in the morning, the dishes already inside were covered with ants. She would of course run the dishwasher, which seemed to solve the problem until a few days later when ants appeared on the new dirty dishes.

After inspecting the house and property, we found no ants anywhere. Nothing in crawl space or dishwasher safe plumbing lines. Not an ant in sight. We figured the colony should be located in a wall void near or under the backs of the cabinets, so we treated those areas carefully. But that didn’t solve the problem – she would still find ants on yesterday’s dirty dishes in the dishwasher. I thought, OK, there’s no way for ants to get into the dishwasher without going through a treated area. They must be inside the dishwasher.

With the customer’s permission, we took the dishwasher apart and you wouldn’t know, they were all tucked away in the front control panel. They never had to leave because they received food and water through dirty dishes. We took out the control panel, swept away the ants and then put the dishwasher back up. They thought they had outsmarted us. But not this time. (Although my head hurts from banging it against the wall trying to figure this one out. They almost drove me crazy.)

The author is Technical Director at Terminix Service, Columbia, SC

Click below to see Argentinian ants in action

(Video source: Service Terminix)



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