Pest Patrol: Abolish Those Aphids

Aphid populations can increase rapidly on a plant. Luckily, there are six simple ways to control them.

Summertime can be a great time for outdoor fun — sun, sand, games and enjoying the landscape you’ve worked hard to cultivate and nurture. However, summer can be a stressful time as well, particularly for your plants.

Heat, wind and sun can cause your plants to lose water more rapidly than usual and create stress that makes them susceptible to diseases and insects. One of the insects that loves water-stressed plants is the aphid.

There are many species of aphids that infest landscape plants, feeding on plant sap and excreting the waste product as honeydew (sugar water). Aphid populations can increase rapidly on a plant in the absence of insect predators or other methods of management and, in what seems like overnight, can severely damage the plant’s ability to make energy from its leaves. Aphids like to feed on the underside of the leaves and along the plant stem. A secondary problem caused by the honeydew deposits on the leaves is the development of powdery mildew and other molds on the leaves.

How can you deal with aphid populations that are out of control or may soon be out of control? There are some easy and fun ways to do this.

  1. Crush a few aphids on the spot: a crushed aphid releases alarm chemicals that signal to the other aphids danger is near. They will drop off the plant and become vulnerable to predators.
  2. Insect predators: ladybugs and lacewings are perhaps the best predators of aphids in the landscape. Ladybug and lacewing larvae are voracious predators and eat several hundred aphids per day if food is plentiful. Most of the time, Mother Nature will answer the call, but to assist, you can purchase adult ladybugs or cards of lacewing eggs online or in local nurseries for release in your garden or landscape. There are also tiny parasitic wasps that attack aphids as well.
  3. Strong streams of water: spraying infested areas of the plant will knock the aphids off and onto the ground. Aphids are poor crawlers and it takes them a while to return.
  4.  Make an aphid trap: Use a bright YELLOW disposable plastic drinking cup and cover the outside of it with petroleum jelly or use a bright YELLOW index card and cover both sides with spray adhesive. Hang the card or place the cup on a stick or other means with the open side down among your landscape plants. Yellow is highly attractive to aphids, whiteflies and fungus gnats.  They will be attracted to the yellow color and become ensnared in the trap.
  5. Pruning: prune off plant areas that are severely infested or diseased and discard them.
  6. Provide adequate water to plants: Although most landscape plants can handle long periods without water, providing regular, but occasional doses of water keeps plants healthy and allows them to stave off attacks from insects and disease.
Picture of Nathan Riggs
Nathan Riggs
Nathan Riggs is a SAWS project coordinator and licensed irrigator who also happens to have a degree in entomology from Texas A&M University. Yes, Nathan’s a bug expert, and not just on water bugs! When he’s not hard at work on SAWS conservation projects, he enjoys a wide variety of interests including: landscaping, hiking, photography of flowers, insects and other critters, and planning his next adventure with his wife Ella and family.
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