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Got ants on your plants? Don't worry. Winter will soon be here.
Each
summer, determined gardeners wage a losing war against ants. Despite a
vast arsenal of weapons - poisons, boiling water, cornmeal and even
eucalyptus oil - used to exterminate them, the ants keep marching one
by one. These methods may give gardeners high hopes for keeping ants in check but do little to rid the landscape of ants.
And while that might frustrate gardeners, it's good news for the environment.
Ants
are essential to the ecology. Besides being some of the most important
insect predators, they disperse seeds and aerate the soil. With about 20,000 species of ants in the world, exactly how many ants are there?
"You
don't want to know," says Whitney Cranshaw, author of "Garden Insects
of North America: The Ultimate Guide to Backyard Bugs" (Princeton Field
Guides, 2004). "There are tens of millions of ants, and they kind of
run the world." Cranshaw is an entomology extension specialist with Colorado
State University Cooperative Extension. "What's the harm of ants?" he
asks. Trying to "eliminate ants is a pointless exercise." Ants may be a nuisance, but they aren't considered pests.
They offer gardeners more positives than negatives, especially when it
comes to protecting plants from the real pests. Ants in lawns are busy eating other insects, which means
fewer lawn problems, says Cranshaw. Ants are expert earthmovers and can
move more dirt than earthworms. Sometimes their tunneling while building nests causes plant
damage by disturbing the soil around roots. But the damage on plants
may be the result of aphids, not ants. Ants do protect aphids from
other predators to keep a supply of the sweet honeydew that aphids
secrete. The honeydew is taken back to the colony to feed developing
ants. "The ants defend the aphids against their natural enemies like the lady beetle," Cranshaw says.
That's the only time Cranshaw takes measures to control ants in his yard.
Managing
ants by pouring boiling water on hills doesn't work because it can't
get deep enough to reach the entire colony. And forget about the urban
legend that sprinkling cornmeal or grits near active nests will cause
ants to explode while digesting dinner. When Cranshaw goes after ants, he treats specific plants.
Barriers placed around the base of the plant will keep ants off but
will allow beneficial insects to move in. Use either a sticky substance
or a physical barrier to keep ants from crawling up the plant stem. Ants might indicate an aphid problem, but ants tending their
aphid flocks aren't a big deal in the total picture, Cranshaw says. Experts say that ants have the largest biomass of any group
of animals on earth. They are insects that grow to adulthood from eggs.
"If you see an ant walking around on legs, it's an adult. Small ants
are a different species, not baby ants," Cranshaw says. Winged ants, which look like winged termites, appear when
breeding. This usually happens in midsummer after a big rain. It's
easier to establish a new colony when the ground is soft. "Males die within a day or two, and females set up a new
colony. You may see them one or two days in a row, and then they'll be
gone. It's just the way they reproduce," Cranshaw says.
Colorado is home to at least seven kinds of ants. They include field ants, cornfield ants, carpenter ants and
pharaoh ants. Fortunately, fire ants don't like the state.
"The ants we have here don't cause any serious stings, just tiny
pinches," says Cranshaw. That's a bit disappointing to an insect
aficionado. "We don't have any good vermin up here," he says. Ants in the garden are valuable for pest control, but ants in
the house are a different matter. Ants that like to nest indoors
include pavement ants, pharaoh ants and thief ants. The most effective
controls for indoor ants are removing food sources and treating
perimeters, which prevents the insects from entering. Cranshaw says ant baits are the best method for extermination. Ants feed on the bait and return it to the colony.
Ant
traps can be purchased or made at home with a little boric acid mixed
with an appetizer. Field ants prefer something sweet, like honey or
apple jelly. Pharaoh ants prefer something oily like peanut butter and
honey. Be sure to keep the ant traps away from children and pets. Cranshaw says that if ants were eliminated completely, the
ecosystem would collapse. While we rely on ants for eating insects, in
other parts of the country, there are plants that depend on ants for
seed dispersal. Cranshaw says it is best just to leave ants alone. "They have
little impact on us, and you're not going to get rid of ants. Your
efforts are for naught."
Amazing ants
The insects live in large
colonies, can carry more than 25 times their weight, and communicate
with each other using their antennae. Here are some ways to enjoy ants..
Observe the
creatures. With Uncle Milton's ant farms, you can watch ants tunnel and
build roads (towerhobbies.com, 800-637-6050). Or in the space-age ant
habitat called AntWorks ants tunnel through a blue gel derived from a
NASA space experiment. The gel is both habitat and food for the ants
(thinkgeek.com/cubegoodies). AntHill, designed like a real ant's home,
includes cross-cuts for easy observation (insectlore.com). Watch ant movies. Two animated films are "Antz" and "A Bug's
Life." If you're feeling adventurous, rent 1954's "Them!," a classic in
which a colony of gigantic mutant ants tries to conquer the world. Make "Ants on a Log." Fill lengths of celery with cream cheese or peanut butter; top with raisin "ants" and enjoy.
Read
a Pulitzer-prize winning book. "The Ants," by Bert Hölldobler and
Edward O. Wilson, contains everything you ever wanted to know about
ants. A kids website. 42explore.com/ants.htm provides facts, activities and links to ant sites, including an ant webcam.
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