Little fire ants can make life miserable

Help! For over a year now in Leilani Estates, we have been plagued with little red fire ants. They first showed up outside around our cat food bowls, and I’ve learned to put the pet bowls in the middle of paper plates that have a liberal ring of diatomaceous earth around them and that seems to keep them away from the pet food. They then came into the house, mainly around the kitchen and bathroom sinks. Vinegar water seems to disperse them on my kitchen counters and a trail of Amdro helps some. Outside around the house we’ve tried OrthoMax, both liquid and powder, and Amdro baiting, but they are still making our lives miserable with their very large welts that sting and itch for days. Do you have any suggestions of how to get rid of them permanently? — Unhappily scratching in Pahoa

Although I have discussed the little fire ant (LFA) in this column before, I want to repeat some information since this is such an annoying and painful pest.

Anyone who is battling the LFA needs to go to Dr. Cas Vanderwoud’s website at to find the latest information on LFA.

Here is a summary: A three-pronged attack is recommended along with a whole property approach. Spot treating is inadequate.

1. Place ant baits in infested areas. In general, this is done to control ground nests. The ants will take the bait back to their nest and share it with others. Baits are the front-line tool for ant control. This approach should be tried first. Wait a couple weeks before applying barrier treatments.

2. Barrier treatments — the application of insecticides (liquid or granular) around areas where ants need to be excluded. As ants crawl over the treated areas they are killed. The more ground you treat, the better. However, if you want to limit your use of chemicals, treat those areas where you want the most protection, areas most used by people and pets.

3. Ants nesting in trees may not be controlled by the bait applications. Therefore a foliar insecticidal spray, applied to infested trees and vegetation, is needed.

There is good news that a new material called Tango is now available for the control of ants in the garden, around certain food crops and in the home.

Although expensive, it is a very effective tool for the control of the LFA. Tango is an insect growth regulator which works by preventing affected insect larvae from completing their life cycle. In addition, egg production by the queen is either slowed or prevented. Ant colonies baited with this material slowly die out over a period of months. See the LFA website above for more details on this product. Be patient; persistence is the best weapon.

You state commercial trees are often topped to a height of 10-12 feet. I would like all my fruit trees to be at that height. Do you wait until they are at that height and then keep topping them every year? Or do you start when they are smaller? Do different trees respond differently to topping? Thanks for all your great information. — W

In most cases, fruit trees are pruned to let light into the canopy for better fruit production, to allow for more efficient pest control sprays, to rid the tree of dead and diseased branches and to facilitate more efficient picking. By and large, it is wise to limit the height of fruit trees for ease of picking. I would wait until the trees obtain the height at which you want to maintain them, or perhaps just beyond. Then prune, let’s say every one to three years, depending on the vigor of the tree.

Trees can often be topped by a simple hedging action. However, occasionally you will need to selectively thin out some branches. As a general rule, fruit trees respond well to topping; some recuperate quicker than others.

Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years. Email your questions to Sakovich at


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