Ants In Your Plants (or Pantry)?
By Bob Chapman
Ants are found in every part of the world except Antarctica and the Arctic. But, I’m sure you would agree that if you were able to have a picnic in the Arctic, ants would join you before the last bite of food were eaten! There are lots of species of these social insects but gardeners need only be concerned with the eating habits of two types: the sweet eating and the meat-eating ants.
Friend or foe?
Ants are viewed by many as their enemy, especially when a trail of them are seen crossing the kitchen counter. Yet, ants are very excellent scavengers and rarely feast on our shrubs and flowers. When seen in the garden, they may serve as indicators of other insects feeding on our prized plants, shrubs and trees. To understand this claim you need to know something about these smart insects.
Typical life cycle of ants
In the mating season, in spring or early summer, a winged female and a male fly, mate, and then the male dies (one brief fling and that's it for him!). The female, called a queen, locates a suitable nesting site, sheds her wings, builds the nest, enlarges it and then lays eggs. The eggs hatch into larvae, eventually emerging as workers. These workers are sterile wingless females. From this first group comes the work of building and expanding the nest even larger. Then the queen doesn't do any more nest building she just lays eggs.
The workers, always females, scavenge food (dead insects, seeds, fungi, flower nectar) bringing it to the nest to feed the colony. Food may consist of grease, meat or sweets, depending on the species.
Ant species: the sweet-eating ants
The kind gardeners are interested in are the sweet-eating ants. This ant species has learned to "farm" certain insects such as aphids, mealybugs, whitefly, leafhoppers and scales. These sucking insects stick their beaks into the plant tissues and suck the juices. These insects are so good at it that they excrete the excess, undigested sap as a sweet substance called "honeydew." Honeydew is highly prized as a food by the sweet-eating ants. These ants will move young aphids to other parts of the host plant, or even to another plant, thus "farming" them. Ants are adept at milking the aphids, stroking them to encourage the release of tiny droplets of honeydew, which they carry back to the nest.
Controlling ants in the garden
Wise gardeners look for ant trails heading into plants and trees as they know that hidden from view is a destructive, sap-sucking insect being farmed by the ants. The ants protect their "farm" by deterring predators of aphids, scales and other sucking insects. In addition to deterring ants you may, or may not, need to get rid of the harmful insects.
“Tanglefoot” will keep ants out of trees and shrubs. Ants are not able to cross a band of the sticky stuff. To use, wrap the trunk with a three-inch-wide band of masking tape. Make sure that you press the tape into each crevice or the ants will crawl underneath the tape. Use a stick, such as a paint stirrer, to spread the sticky Tanglefoot over the tape. Do not allow the Tanglefoot to contact the bark of the tree or shrub. Replace the Tanglefoot and the tape annually.
You don't necessarily need to kill the ants (it's like killing the messenger and letting the evil ones live!), but determine which harmful insect is attacking the plant and eradicating the insect, if needed. Remember that ants seldom harm plants or flowers. Most often the natural predators of the sucking insects will keep them under control once the ants are kept away.
Ants found in the garden can be controlled, if desired, with malathion, permethrin, products containing boric acid (or its many derivatives) or sevin.
Controlling ants invading the home
Entering a room in the house, especially the kitchen, to see a steady stream of ants is an unsettling experience. Ants generally stick to the outdoors but will enter a home seeking food after a rain. Most often they may leave after the ground dries outside.
There are various methods to control the invaders: denying access, spraying insecticides or placing baits near their entry point or wherever their food source(s) may be.
The quickest way to eradicate them is using an aerosol ant killer. Some have a residual chemical that will keep ants away for several months.
Baits are available containing boric acid (or its many derivatives) or hydramethylnon, both effective eradicants. Placed out of reach of small children, the baits last for a long period of time.
Ants enter the home through cracks in walls and windowsills, openings around water lines, heating vents, drains, wastes and vents. When a stream of ants is found, try to locate the entry point(s). Plug these entry points with “Polyfoamseal.” Polyfoamseal is an expanding foam-like substance in an aerosol can. When sprayed into an opening it expands to fill the space, including crevices. Once an opening is filled with the stuff, no ants or other bothersome insects, such as earwigs or sowbugs, can enter. It is quick and really easy to use, can be removed and takes but a few minutes to seal all the possible openings in a room. Once done, it permanently denies entry by insects and no sprays or baits are needed in the future.
Sources of supplies
Tanglefoot and ant baits and sprays are found in the inside garden department of our stores. Polyfoamseal is found in the industrial hardware department. Our helpful sales associates will be happy to show them to you.