DALLAS GARDEN BUZZ

A school of fish, a mob of crows, a gaggle of geese,   A “herd” of aphids?  Well, if you are from an ant species called “dairying ants” or “sugar ants,” you might call groups of your aphid charges just that.

Above: A Herd of Aphids

As many gardeners know, aphids can be a common problem on plants, especially during the heat of the summer.  These soft bodied insects suck plant sap, wither foliage, and cause a generalized lack of vigor in plants.  Aphids come in many colors (yellow, white, green) depending on the type of aphid and the plant that they are feeding on.  One of the most interesting facts about aphids is that some are said to be “born pregnant.”     Though many aphids mate and lay eggs to reproduce, some aphids are capable of a true  “virgin birth.”  These parthenogenetic generations are produced by unfertilized females.

Aphids not only suck plant sap which eventually withers the foliage, but they can spread diseases from plant to plant.  When feeding on a plant, aphids excrete a sugar substance from their anus.  This substance, called honeydew, is very sticky.  It can also form the substrate for a black mold which blocks out the light from a leaf, thus leading to the further decline of the plant.

Above: Yellow Aphids Close Up

In the garden, ants and aphids are often seen together on infected plants.  In my experience, beans, peas, and okra seem to be some of aphids’ favorite plants and harvesting produce from these plants is often a challenge from biting ants.  These ants are drawn to the honeydew, which is a perfect food for the ants.  To increase their supply of honeydew, the ants tend aphids like cows.  These sugar/dairying ants “milk” aphids by stroking the aphids with their antennae until they release a drop of sweet honeydew liquid. They even keep their “charges” from straying by chewing off the aphids’ wings.  In the fall, the ants carry aphid eggs into their nests, to be carried back out in the spring and set on the plants.

If you are having problems with aphids and ants in your garden, there are several environmentally safe methods of aphid control.  One of the best methods is to spray the plants with a hard stream of water.  This will kill some of the soft-bodied insects (it decapitates them) and the water will wash many others off the plant.  This method is said to be 80% effective, even better than some chemical controls.

Another environmentally safe control method is to be patient and “let nature take its course.”  Within a very short period of time, where you see aphids, you will also see lady bugs (lady beetles) laying their bright orange eggs on the leaves of infected plants.  The lady bug larva, which looks like a miniature spined alligator, is a voracious consumer of aphids.  Studies have shown that each larva can eat up to 40 aphids in a single hour.  This has earned the larva the name of “aphid wolf.”  Other important beneficial insect predators include soldier bugs, damsel bugs, big-eyed bugs, spiders, assassin bugs, syrphid flies, gall midges, and lacewings.

Above: Ladybug to the Rescue!

So if you are having problems with aphids and sugar ants, before you get out the chemicals, try some of these low impact methods of aphid control.  Not only will you be able to get aphid damage down to an “acceptable” level, but your biting sugar ant problem will decrease also.

Carolyn

Pictures by Starla