You don’t want aphids on your backyard guest list. “They have mouthparts like little sodastraws, which they use to suck juices from plant cells,” she said. The feeding weakensplants and causes wilting, but that’s only part of the problem. One way to keep aphid populations down in your yard, she said, is to avoid buying themon new landscape plants. If you find the little hitchhikers, look for other plants, Sparks said. You have enoughproblems at home without buying more of them. The tiny gluttons suck up more plant juices than they can digest. The part the aphids’bodies can’t use passes through them as a high-sugar excretion. You can also spray plants with an insecticide labeled for aphids or use an insecticidal soap.Whatever you use, though, be sure you spray the right places. Looking at their rear ends through a hand lens, she said, you can see what looks like twotiny tailpipes. Aphids are the only insects with these dual-exhaust cornicles. Those landscape plants may be just what you wanted, but before you take them home,check them closely anyway. You may find some unwanted hitchhikers. “Check closely for signs of wilting, curling of new growth and sticky upper surfaces onlower leaves,” Sparks said. “Look for the aphids themselves on the stems and underside ofleaves on the newest foliage.” The pests will be concentrated on the newest leaves and stems. So carefully prune off theheavily infested foliage. Put the pruned parts into a plastic bag and get rid of them. “As the weather warms,” Sparks said, “we’ll see more problems with crape myrtle aphids.” Aphids infest almost any annual or perennial plant and many of the more common woodylandscape shrubs. Two species causing problems in late April were green peach aphids andmelon aphids. To see the aphids, she said, use a hand magnifying lens. Or shake the foliage over a pieceof white paper. The soft-bodied insects are the size of a pencil point. This sticky “honeydew” drops onto leaves or anything else beneath them. And to add thefinal insult, various fungi feed on the honeydew and create a black coating, called sootymold. It’s not a pretty picture. If you already have aphids on plants in your landscape, check closely to see if you alsohave beneficial insects. “Lady beetles can clean up an aphid population,” she said. “Don’ttreat for aphids if you have good populations of lady beetles or lacewings.” If you don’t have enough good bugs, you’ll have to get rid of the aphids yourself. “Aphids are hard to control in a greenhouse or nursery environment,” said Beverly Sparks,an entomologist with the University of Georgia Extension Service. “By the time they getto the garden centers, many plants can have small aphid populations.” The worrisome pests are so small you can hardly see them. “The problem,” Sparks said,”is that populations can build to such large numbers that they cause serious injury toplants.” “To control aphids,” Sparks said, “you have to get thorough coverage on the underside ofthe leaves.”
"Avoid Hitchhiking Aphids"