By Glenn I. Teves, UH County Extension Agent
Ants are among the most prevalent pests affecting our households and yards. Once established, colonies are difficult to control and present a formidable challenge. Ants are some of the most ancient and most organized insects, and some even bite. In studying their habits, some guys at the state Department of Health Vector Control Branch found a two-mile-long colony of long-legged ants in Kaneohe, Oahu! This same ant, first discovered on Molokai in Halawa Valley, has been seen in Kaunakakai and is not easily attracted to bait.
There are basically two kinds of ants in terms of their feeding habits – sugar lovers and protein eaters. Sugar lovers like all kinds of sugars, some kinds more than others, while the protein eaters will eat grease, seeds, and anything with protein in them. There’s also a small group that feed on cellulose or paper and card board.
Boron compounds, such as boric acid powder, are very toxic to ants, but very safe for us. Mixing an attractant with boric acid is the way to knock them out. However, eradication is difficult, so controlling them when you see them is the way to go. Some sugar-loving ants can be a challenge because they’re particular about what kind of sugar they prefer. Vector Control discovered a mixture of three parts of saturated boric acid solution, 40 parts honey or karo syrup, and 57 parts water were able to control them. The first step is to make saturated solution of boric acid in warm water to dissolve the boric acid, then mix everything together. The Department of Agriculture has a slightly different mixture, combining three cups water, one cup sugar or a sugar compound such as honey or karo syrup, and four teaspoons boric acid powder. Apply baits in areas where you know ants will frequent.
The big-headed ant is common on Molokai, and probably one of the most adaptable ants because they are both protein-loving and sugar loving ants. This phenomenon is not well understood, but in the wild they can feed on small seeds, flowers and even honey dew.
Recent research has developed many new ant baits, but keeping them effective over a long period of time, especially in our environment, has been a challenge. Amdro, an ant pesticide applied to soy bean granules, is very effective against protein loving ants. The active ingredient is very photosensitive so it must be applied in the dark or late afternoon. Overnight, the ants will pick it up and take it back to their hive where it can kill all ants that feed on it. By enclosing this compound in feeding traps, it will increase its effectiveness by almost a year by overcoming its photosensitivity. You can even buy it in little bait stations.
New ant species are a constant threat to the Hawaiian environment because they’re very mobile and difficult to detect. If you find an ant and want to try your hand at identifying it, you can use this handy key: http://www.discoverlife.org/mp/20q?guide=Ants_Hawaii&flags=not_no