Skip Navigation

UNL

Horticulture Pest Update - Winter

submitted by Mary Jane Frogge, Extension Associate
Monarch on a Zinnia

Scale Insects Photo Above
White Fly Photo Below

White Fly

Now is the time to watch for...

Household Plant Pests: Scales, Mealybugs, Whiteflies

MealybugSeveral species of scale insects, mealybugs (photo left) and whiteflies are commonly found on plants in the home. All are sap-feeding insects that can weaken plants and cause poor, stunted growth. Death of infested plants occurs only in severe cases.

Houseplant insects may create an annoyance caused by large quantities of a sweet, sticky liquid waste product called honeydew that is excreted as the insects feed. Honeydew can make a sticky, shiny mess on the plant and nearby furniture and floors.

Scale insects (photo right top) have a tan to brown shell-like covering or scale that protects the insect's body. Scales may be from one-sixteenth to one-forth inch in diameter and are usually found on the stems and/or leaves. Some scales are hemispherical in shape, while others are oval and flat. Mealybugs appear as white tangles of cotton on the leaves or stems. A common location is the slim, protective gap at the junctions of stems and leaves. White flies (photo right bottom) are tiny white insects that feed and lay their eggs on the underside of plant leaves. When an infected plant is disturbed, the tiny insects take flight and then return to the host plant.

Houseplant insects are difficult to control. There is no easy, simple, one-shot cure. One possibility is to pick off individual scales and mealybugs or gently scrub (or rub) the insects loose from the leaves and stems. This is a laborious task that works only on small, large-leafed plants. Dabbing each insect with an alcohol-soaked cotton swab is another possibility on lightly infested plants.

(This resource was updated January 18, 2006. For information on reproducing this resource or using any photographs or graphics, read the Terms of Use statement)

Return ArrowReturn to Horticulture Pest Update - http://lancaster.unl.edu/hort/pest/

University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office