Aphids — nasty little black bugs
Last year we had a major infestation of black aphids on shallots and garlic. We’d seen these bugs in previous years on chives, but never this many. Here’s what to do if aphids try to take over your garden.
Aphids are tiny soft bodied insects that suck the juices out of plant tissue, stunting the plant’s growth. They come in many colors, including green, black, brown, red, white, and pink. More than 4,000 species have been identified. They rarely lay eggs, but give birth to live clones of their mother. The reproductive cycle is short, so a tremendous increase in their population can occur in a short time.
The first indication of aphid problems is often deformed foliage. Or ants and wasps start to show up, feeding on the honeydew that aphids excrete. Inspecting the underside of plant leaves regularly will help catch the problem before significant damage occurs.
Aphids have lots of natural enemies, including lady beetles and parasitic wasps, so you can afford to be patient if ornamental plants are infested. But in the vegetable garden you need to be more aggressive. Organic insecticides are just as effective as synthetic chemicals in controlling aphids. And with organic insecticides you can harvest treated crops the same day, instead of waiting seven days or more with a synthetic chemical. But whatever insecticide you use, cover all areas of the plant completely, especially the nooks and crannies on the underside of leaves. More than one application may be necessary.
If you see aphids, my recommendation is to use insecticidal soap. Two applications took care of our infestation last year. I do not recommend dishwashing liquid as a substitute. The main ingredients in both dishwashing liquid and insecticidal soap are similar if not identical, and either will kill a wide range of bugs. But dishwashing liquids have perfumes and other chemicals to make their use in the kitchen more pleasant, and I don’t want those chemicals on my vegetables and ornamental shrubs. Insecticidal soap is pure soap, without any of these additives.
Keep a lookout for aphids this year in your garden.
Jim Janke is an Extension Master Gardener Volunteer in Haywood County. For more information call the Haywood County Extension Center at 456-3575. © 2014 NC State University.