LANGFORD: How to 'uninvite' tiny visitors

By Dale Langford, Special to the Rocky

Published January 26, 2008 at 12:05 a.m.

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Unwanted visitors may have entered your home with this season's gift plants. It's also common to find abundant "live-ins" on your own houseplants brought in from outside in the fall.

Pesky bugs can come in through open doors or windows, too, so there's no reason to believe your plants are pure.

The most common of these pests can be controlled with the steps listed below, or you can apply insecticidal soaps. This soap spray has been approved by the EPA for use on both edible and nonedible plants.

These soaps contain fatty acids that penetrate the bugs and kiss them goodbye. Insecticidal soaps have no bad effects on birds, pets or people, so they're safe to use indoors and out.

The soap must be sprayed directly on the insect, so be sure to get the undersides of the leaves.

For best results, lightly mist the plant. Apply the control to neighboring plants, which may also have started to harbor these "guests." Respray a couple of times at 10-day intervals to catch hatchlings.

You also can put the plants in your sink and spray with water to dislodge pests like spider mites and aphids. Hold smaller plants upside down and flood the foliage from the faucet with lukewarm water.

Here are some common sap-sucking pests:

* Spider mites: If you shake leaves over a white sheet of paper and some of the dust specks that fall off move around, you have spider mites. Other symptoms include webbing and leaves that look like they have been poked by needles. These insects like warm, dry spots, like sunny windows and heat vents. The females, if left uncontrolled, can produce thousands of eggs a month.

* White flies: If leaves turn yellow and start to dry out, you'll find hundreds of adults and youngsters on the undersides. Shake the plant and a small cloud of miniature flakes dart away. White flies are tough to get rid of, but a continuing spray program can make them go away. They are also attracted to bright yellow objects. Commercial sticky bars or strips work well; a yellow plastic cup with a thin coat of honey will also work.

* Mealybugs: These look like little tufts of cotton, 1/8 to 1/4 inch long as adults and so small in the crawler stage they're hard to see. They usually attach themselves where stems and leaves join or along the veins of leaves. The fluffy white wax that covers the adults is hard to penetrate, so thoroughly spray the plant to run-off. A toothpick poked into cracks and crevices will do away with any survivors.

* Aphids: These are more familiar outside in summer, but once they get established inside, look out. Hundreds will gather on the newest, tenderest stems and leaves. They stunt plant growth and often cause leaves to distort. They produce a residue called honeydew that makes leaves sticky and unsightly.

All these pests do their damage by inserting mouth parts like soda straws into plants and sucking out the food-rich juices. They're tiny, but they cause damage by virtue of massive numbers. It takes only one person paying attention to your houseplants to keep these armies at bay.

Dale Langford is an area lawn and garden specialist.

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