Aphids and their Management

Aphid damage may appear as pale yellow spots on leaves, leaves that are curled, puckered, or stunted, and/or distorted blossoms. Another telltale sign is the sooty black layer they leave behind on the leaves. Because aphids suck more plant sap than they can use, they exude a sweet honeydew substance onto leaf surfaces that molds quickly. This soot can become very unsightly and can interfere with the respiration of the plant.

Alternative Solutions:

·        Introduce beneficial insects into your garden. Green lacewings (sometimes called the "aphid lion") are the best organic defense again aphids. After a few days, the eggs hatch and tiny larvae emerge with a voracious appetite. There is no better predator known to consume vast quantities of eggs and the soft bodies of aphids, mealy-bugs, spider mites, leafhopper nymphs, caterpillar eggs, scales, thrips, and whiteflies. The ladybug and the praying mantis also have a taste for aphids and can prove quite effective in an organically managed garden.

·        Use an insecticidal soap, but in moderation, as it will kill beneficial insects as well as the aphids.

·        Spray your garden with silica Aerogel/Pyrethrin. This product that will dissolve the cuticle layer on the insect causing it to dehydrate and die.

·        Use Neem Oil.*

Chemical Solutions:

Suggested insecticides for use against aphids include acephate/fenbutatin-oxide combination (Ortho Systemic Insect Killer), carbaryl (Sevin), imidicloprid (Merit), tau-fluvalinate (Mavrik), biphenthrin (Talstar), permethrin (Immunox), and acephate (Orthene).

Because our gardens border neighbors who liberally use chemicals, organic gardening is not a practical choice. We have found imidicloprid to be the most effective against aphids in our own gardens.

Neem Oil

Neem oil is a botanical pesticide made from an extract of the plant Azadirachta indica. When the oil is distilled from the plant's seeds, its concentrated mixture contains high amounts of the active chemical azadirachtin. It doesn't strongly affect humans, mammals, or beneficial bugs, and it has been proven as an effective insecticide and miticide. When sprayed on plants, Neem oil repels harmful insects like white flies, gnats, aphids, mites, and weevils, as well as reportedly strengthening the crops against rust, scab, mildew, and blight. Edible crops of vegetables do not get poisoned when neem oil is used. Additionally, Neem oil makes plants taste bitter, so pests won't eat them, thereby functioning as a "contact" insecticide. Azadirachtin also interrupts insects' transitions between different stages of metamorphosis, such as growing from larvae to pupae. It prevents insects from developing a hardened exoskeleton. When the chemical gets absorbed through the roots of plants, it functions as a "systemic insecticide." That means crops don't need to be constantly re-sprayed. Perhaps the greatest lure for using neem oil is that it doesn't harm beneficial insects. Butterflies, earthworms, bees, lacewings are all safe in your garden.

Sounds too good to be true, doesn't it? Well, for the Southern gardener, it just might be. Neem oil is just that… an oil. Just like the dormant oil sprays that burn our plants when it gets too hot, Neem oil will too. So, about the time that the whiteflies and aphids are most active, Neem oil will have to find it's way back onto your shelf until the weather once again drops below 75 or 80 degrees.