July 6, 2010
My peppers and squash are sticky all over and the leaves are splotchy and look like they’re going to fall off. What’s going on?
A. Every year is a new adventure for gardeners and homeowners. Your problem is familiar to many, but don’t fret – there’s hope for your garden, yard and sanity. The “sticky stuff” is likely what’s known as “honeydew.” It’s the by-product of aphids, who are feeding on your plants or a tree overhead. Aphids are sometimes called plant lice, and they come in several different colors. Populations can increase rapidly in the right conditions, and all feed on the sap of plants.
They’re very small but feed in gross numbers. Aphids are usually visible on the undersides of leaves, stems and in the nooks close to new growth shoots. The honeydew is a nuisance. It’s sticky and attracts ants, as is a food source for a black colored fungus that can discolor trunks of trees and foliage and interfere with plant health. Large aphid infestations can have a negative impact on plant vigor and vitality. Fortunately there are cures.
The first cure may already be present: ladybugs. The ladybird beetle is a prime predator of aphids, especially the immatures that are often called an “alligator.” These little six-legged larvae are gray or black with yellow or orange spots or stripes. Green lacewings, syrphid flies and parasitic wasps also feed on aphids, and all may be present in your yard, effectively reducing the aphid populations. An immediate and effective control is to spray your plants with a garden hose to wash off the aphids and honeydew. If the problem persists, then look into an insecticidal soap or horticultural oil. Finally, if the aphids persist, there are many insecticides available, such as acephate, bifenthrin, malathion, esfenvarelate, orthene and imidacloprid. Quite often, aphid populations decline and the plants will be just fine.
If you need more recommendations, please call your local Extension Office for advice, or visit the CSU Extension website at http://www.ext.colostate.edu.