What Are Those Little White Insects on My Tomato Plants?

Greenhouse White Flies on Tomatoes

• Greenhouse white flies are small sap-sucking winged pests that attack many species of plant life. They can be seen on tomato plants by close inspection of leaves and stems or by shaking the plant gently. They usually swarm up, making them visible to the gardener. Greenhouse white flies are tiny at less than 1/8 of an inch long with tiny white wax-coated wings. They can be removed from tomatoes by spraying with a warm soapy water mixture. To prevent problems, all soap residue needs to be rinsed off with water after killing the white flies.

Aphids on Tomato Plants

• Aphids like white flies are tiny sap-sucking insects that attack tomato plants. They are usually along the stems and undersides of the leaves. A plant infected with aphids will begin to lose its healthy green coloring and fade to a sickly yellow. If left untreated, plants can be killed by aphids.

Mealy Bugs on Tomato Plants

• Mealy bugs are very tiny, 1 to 4 millimeter long insects that often attack garden plants. They are found on the stems, leaves and fruit of tomatoes and are recognized as small oblong fluffy-looking maggots. Males have wings and at times are mistaken for gnats, female mealy bugs are wingless; some even have two "tails" extending from their rear. Plants suffering from mealy bug infestation will begin to turn yellow and can develop a black sooty mold. Mealy bugs have toxic saliva that distorts plant growth and affects their aesthetic value.

How to Prevent Pests on Tomato Plants

• A healthy plant is less likely to suffer from illness or pests. Keep tomato plants well fed and watered all season long. Good airflow is also essential in preventing common problems like blight, fruit drop, aphids and white flies. The best time to treat for pests is as soon as they are noticed on plants. The longer one waits the more difficult it is to treat said issue. Check the soil around each plant as the insects will sometimes fall and can be hidden from view. To ensure hidden pests die it is best to flush the soil of each tomato plant with soapy water with each treatment.

How to Kill Tomato Pests

• The use of biological pest control is gaining popularity and for good reason. Many of the natural control methods exercised today are environmentally friendly. One ladybug will eat as many as 5,000 aphids in its lifetime. Braconid wasps are beneficial parasitic wasps. They are tiny and pose no threat to humans or pets. They kill aphids by laying their eggs in them. The eggs hatch and the wasp larva eats the aphid from the inside out. Common dish soap mixed with water will kill aphids, white flies and mealy bugs.