Insect Hitchhikers

Insect problems usually come in as new plants are brought in from outside the home. These often have hitchhikers on them that infest other plants because they have no natural enemies inside the home and have ideal conditions to reproduce. Insects also enter through doors, windows or other openings to the home. Prevent insect buildups by periodically washing the backsides of the leaves over the sink. This keeps the foliage clean and removes both adult insects and their eggs. When insects are already a problem, control them by using a mild detergent solution in a bucket or tub so that all the foliage can be submerged in the soapy water for about 30 seconds. Handpick visible insects from the plant when they first get started. Use alcohol on a swab to get rid of small or non mobile pests. These insects are the most likely to cause problems on your houseplants. Aphids are soft-bodied sucking insects 1/16- 1/8-inch long. They feed on newest leaves and stems and flower buds. They vary greatly in color. Both winged and wingless forms are found. Aphids excrete honeydew that makes foliage sticky and shiny. Mites are so tiny that they are difficult to notice with the naked eye: Both red spider mites and cyclamen mites feed on houseplants. Infested leaves have a speckled gray-green appearance. Washing the foliage helps. Mealybugs are soft-bodied insects that look as though they were dusted with flour or cotton lint because of their waxy covering. They suck plant juices from stems and leaves. Scale insects are small, stationary pests that suck plant juices from leaves or stems. They vary from 1/16 to 1/4 inch in length. Colors range from white to black. Some have soft shells, others have hard shells. Many infestations go unnoticed because these pests do not move on the leaves once they are established. Sowbugs have oval, gray to brown, segmented, shell-like bodies. When disturbed they roll into a ball. They are more active at night, as they feed on decaying organic matter and small roots of houseplants. Whiteflies are sucking insects that feed mostly on the underside of leaves. The young appear scalelike and do not move about, while adults are 1/16-inch long and winged. Infested leaves become pale, turn yellow, and drop off. Honeydew is excreted over surfaces where both adults and young feed. Springtails are tiny, gray or black insects that jump if disturbed. They do not usually cause much damage but can become a nuisance if they build up to large numbers, Fungus gnats are tiny flying insects that resemble fruit flies. They are usually a more severe nuisance than anything but the larvae will damage the roots if they become severe. If cleanliness does not control the problem then consider using insecticidal soap as a spray. Other houseplant insecticides are available in various formulations for difficult to control problems. Use only labeled products and follow all instruction precisely. Never use pesticides formulated for outside use inside the home. Larry A. Sagers Regional Horticulturist Utah State University Extension Service Thanksgiving Point Office