Mealybugs are part of the insect families collectively known as scale insects. They are soft-bodied, without the outer shell associated with insects in the other scale insect families. Instead, mealybugs are usually covered with a white waxy powder
Mealybugs have sucking mouthparts. Feeding weakens and stunts plants, causes leaf distortion, yellowing, and even total leaf loss. In some cases, plants can be killed. Mealybugs also produce large amounts of honeydew (similar to that produced by whiteflies and aphids), which can coat plants and surrounding surfaces with a sticky layer. A black fungus commonly known as “sooty mold” grows on the honeydew. The presence of honeydew and sooty fungus is one way to detect infestations of these insects.
Life Cycle. The citrus mealybug female can produce about 600 eggs, which are produced in cottony structures called ovisacs. Eggs may be produced with or without males. The eggs hatch in less than 10 days into small nymphs called crawlers. The crawlers move about the plants and locate feeding sites. Once the insects settle, there is not much movement. Under favorable conditions, there may be six generations per year. In reality, generations overlap, so all developmental stages will be present.
Control
Many chemical insecticides list mealybugs.
Non-chemical Control:
– Rubbing Alcohol Spray: Mix 1 to 2 cups alcohol per quart of water. Using undiluted alcohol as a spray is very risky for plants. Since alcohol can damage plants always test your spray mix on a few leaves of plants first. If the spray kills the pests and no leaf damage shows within the next 2 or 3 days, go ahead and spray further, using exactly the same ingredients and proportions you tested. If an infestation is well-established, it will be necessary to make a series of applications, at 10 to 14 day intervals, for mealybug control.
– Insecticidal soap spray according to the dilution on the label but substitute alcohol for half of the water required.
– Horticultural Oil and Insecticidal Soap Sprays: Are effective non-chemical controls for mealy bugs and other soft-bodied pests. Oil sprays suffocate the insects and can aid in controlling scale crawlers and eggs, while soap sprays cause the insects cell membranes to rupture effectively causing it to desiccate.