• Vigorous tomato plants help keep insect problems at bay.Pete Starman/Stockbyte/Getty Images
  
  The tiny winged insects on your tomato plants are a pest problem that can lead to significant damage. An occasional fly is no need for concern, but groups of extremely small insects is a signal that home growers need to jump into action to prevent injury to their fruits. Maintaining vigorous tomato plants is the first step toward avoiding pests which often attack weakened plants or are first attracted to weeds before moving to susceptible tomato host plants.
  
  

Whiteflies

• Whiteflies can quickly become a pest infestation on your tomato plants. These tiny winged insects generally live on the undersides of leaves. Displaying yellow bodies and white wings, whiteflies measure .06 inches in length. As there are many species, among which some cause more damage than others, contacting a local county extension agent is a reliable form of assistance in identifying the precise problem and control solution. As whiteflies feed on tomato plants, the plants' leaves curl and become yellow. This symptom is often accompanied by the fungal infection sooty mold. As whiteflies eat, they excrete honeydew, a sticky sugary substance that attracts and encourages the development of sooty mold. As its name implies, sooty mold results in the growth of black mold on a plant's surface that may prevent the plant from receiving the sunlight necessary for fruit development. Control of these tiny bugs is possible with the release of natural enemies, like parasitic wasps or lady beetles, as a means of natural management. Natural enemies are available from garden supply stores, catalogs and online. For more extreme cases, chemicals with the active ingredient imidacloprid are effective during planting while the insecticide with the active ingredient spiromesifen provides control during the growing season, according to the University of California IPM Online.
  
  

Leafminers

• The tiny winged insects that you see on your tomato plants are often leafminers. The vegetable leafminer Liriomyza sativae, for example, has a wingspan that measures .05 to .06 inches across. Displaying a glossy black body with yellow markings, vegetable leafminer larvae feed on a plant's leaves, creating visible white-hued mines while adults cause a speckled appearance on the foliage as they feed. Leafminers typically feed most heavily during the summer when excessive leaf loss leaves fruit exposed to the sun. Leafminer damage may cause poor fruit development or the loss of crops, according to the University of Florida IFAS Extension. To control leafminers on tomato plants, growers should avoid the use of insecticides except as necessary as chemicals kill both pests as well as the beneficial insects that kill them. If your plants are in need of replenishment of predatory bugs, parasitic wasps provide effective management. For severe problems in need of chemical treatment, the rotating application of abamectin and cyromazine is a reliable control method, according to the University of California IPM Online.
  
  

Aphids

• Of the several aphid generations born on your tomato plants, certain generations produce winged females responsible for leaving the host plant in search of another. Green peach aphids (Myzus persicae) are tiny insects measuring approximately 1/10 inch in length and displaying yellow-green bodies with dark heads. Damage is not considered to be severe; wilting is the most commonly occurring sign of infestation. Though crop loss does not typically occur due to aphid insects on tomatoes, the potential spread of viruses from aphids can cause significant health problems. To control these tiny bugs, the release of natural enemies that hunt and kill aphids, like lady beetles, is an effective measure, according to the University of California IPM Online. Natural predatory enemies may be purchased from garden supply stores, catalogs and online. For extreme infestations, organic control like insecticidal soap or the use of an insecticide with the active ingredient acetamiprid is suggested.