Some Perceived Pests are Beneficial: Ants Have an Important Role in the Garden

From painful stings to destroying wood, ants have earned a bad reputation but every gardener needs a few to maintain a healthy garden.

There are between 12,000 and 22,000 species of ants. Some are considered destructive by human. The rest are fairly innocuous and may even be beneficial. Whether destructive or innocuous, ants like all creatures on this planet play a role in maintaining balance in our environment. To gardeners ants can actually be beneficial as pollinators, increasers of soil aeration, and agents of biological pest control.

Ants as Pollinators
Not all plants rely on bees for pollination. Grasses for instance are almost solely wind pollinated. Plants with colorful flowers may rely more on bees, hummingbirds or moths. Less showy flowers, that are tightly associated with the main stem may be more reliant on ants for pollination. This is especially true if the tiny less showy flowers have sticky substances associated with their stamen and stile.

However, even the showiest of flowers may occasionally get pollinated by ants if there is a way for them to climb up and into the stamen and stile. In addition all these flowers attract bees and hummingbirds with sweet sticky substances that are also attractive to ants.

Ants Improve Soil Structure
Many ants make their homes in soil and in doing so make extensive tunnel systems. Plant roots need air and these tunnels allow air to get into the soil profile. Additionally they increase water penetration in the soil. Ecologists studying the correlations between the presence of ant colonies and plants cover have found more plants associated with ants then where few ant colonies exist. In fact where there are few ant colonies, soil compaction is more prevalent.

Ants as Agents of Biological Pest Control
Most people are familiar with the association of ants with aphids. Ants eat the sticky substance that aphids excrete. Whether ants increase aphids or aphids increase the presences of ants is debatable. However, most people don't notice or overlook the association of ants with dead caterpillars. Not only do some ants eat caterpillars, other ants collect and eat the eggs of other insects.

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Not All Ants are Beneficial
Some ants like carpenter ants and fire ants are destructive or a nuisance. Destructive or nuisance ants should be controlled and this is where gardeners need to be able to identify a few ant species so they know when to apply pesticides or call on exterminators.

Yearly inspections of wooden structures by pest control professions is recommended if you suspect you may have nuisance ants. However, a few pavement ants during the growing season is no reason to spray for ants. In fact spraying these ants is unlikely be effective and will only kill other beneficial insects in the process.

To control fire ants avoid importing nursery stock that has not been inspected your state department of agriculture. If you suspect fire ants have been introduced to your garden contact local agriculture officials for a positive identification.