You work hard to create the garden you love, and obviously you don’t want to see it under attack. Bugs, children, the occasional wild Frisbee – almost anything can destroy the plants you’re trying desperately to nurture. And some plant adversaries are easier to control than others: You can always plead with Jimmy Neighbor Boy not to tromp thoughtlessly through your perennials as he takes his usual shortcut through your back yard. But there’s no such reasoning when it comes to aphids. Fortunately, these common pests can be somewhat easily sent away. (Something, unfortunately, you can’t always say for Jimmy.)

Aphid skins on bud

Like snakes, aphids shed their skin as they grow and leave them behind. These skins are often mistaken for pest insects themselves. If you look closely you’ll see there are no living insects here, so no need to treat the plant.

Photo Credit: ©2003 Buglady Consulting

Sweetpea aphid parasite

This sweet pea aphid has been killed by a beneficial wasp. The wasp lays her egg inside of the aphid. Once the egg hatches, the immature wasp feeds on the aphid, causing the pest to turn papery brown. This is very common in the landscape.

Photo Credit: ©2003 Buglady Consulting

Aphid anatomy

This is a profile of an adult winged aphid (most aphids are not winged). The red arrow points to the cornicles. The blue arrow points to the pest’s strawlike mouth, used to suck up plant fluids and inject saliva.

Photo Credit: ©2003 Buglady Consulting

Aphids are round, soft-bodied insects about 1 to 3 mm long and are normally found in large groups, feeding on plants. They vary in color, from black, brown, green and yellow to red and even pink. Some are covered with a waxy fluff. They are usually wingless, although some are born with wings. (These migrating aphid species, called alates, take off to start new colonies on other plants.) And because aphids tend to give birth to live young, they don’t need to mate, allowing for many generations per year. Combine this with the fact that there are more than 400 species of this garden nuisance out there … well, that’s a lot of aphids.

The key to identifying this common plant invader is to look for tubelike structures, called cornicles, on their backsides. (Cornicles are used to secrete a defensive fluid.) Aphids are also typically found feeding on new, tender plant growth. The adults feed on plant sap using their threadlike mouthparts, which they stick into plant tissue then inject their saliva.

You can tell if your garden is infested by these unwanted garden visitors if you notice any distorted new growth on your plants, such as curled or hardened leaves. Aphids also secrete honeydew through their anus, causing the leaves below the infestation to become sticky. The result is a black, sooty mold that eventually covers leaves and stems. Not only does this mold inhibit infected portions of the plant from photosynthesizing, it’s just downright ugly. But fear not, plant lovers! Aphid infestation doesn’t have to take over your garden like an uncontrollable creature in a bad B movie. The truth is that aphids are one of the simplest pests to control. What’s more, once you treat the aphid problem, the unsightly mold that once covered your plant will go away. (A fungicide isn’t even needed.)

Many natural predators can help combat the pest, such as parasitic wasps, fly larva, lacewing larva and ladybugs. Insecticidal soap and horticultural oils (found in most well-stocked garden centers) can also take care of these pesky visitors. (This won’t, however, protect your plants from Jimmy.)