Whiteflies

Whiteflies are small hemipteran insects of the family Aleyrodidae, found in multiple regions around the world. They are typically found on the undersides of plant leaves, feeding by sucking plant juices. Whiteflies are known for their potential to cause significant agricultural damage through both direct feeding and the transmission of plant diseases.

Description

Whiteflies are small, winged insects that are usually about 1 to 2 mm in length. They are covered with a powdery wax which gives them a white or pale appearance. Their life cycle includes several stages: egg, nymph, and adult. The nymph stages, often called "crawlers," are particularly immobile compared to the mobile adult stage.

Ecology

Whiteflies thrive in warm, humid environments and are commonly found in both outdoor and indoor settings, such as greenhouses. They are known to infest a wide range of plant species, including many commercial crops such as tomato, cotton, and cabbage.

Economic Impact

The economic impact of whiteflies is significant, particularly in agricultural and horticultural sectors. They damage plants through direct feeding, which can stunt plant growth, cause leaf yellowing, and lead to premature leaf drop. Moreover, whiteflies are vectors for several plant viruses, notably those causing diseases like tomato yellow leaf curl.

Management

Managing whiteflies involves a combination of cultural, biological, and chemical methods. Cultural practices include using reflective mulches and removing infested plants. Biological control involves the introduction of natural predators like the parasitic wasp Encarsia formosa. Chemical control, while effective, is used as a last resort due to concerns about pesticide resistance and environmental impact.

Genera and Species

The family Aleyrodidae includes a large number of genera and species. Some of the more well-known include:

• Bemisia tabaci (silverleaf whitefly)
• Trialeurodes vaporariorum (greenhouse whitefly)

See Also

• Insect pests of plants
• Biological pest control
• Integrated pest management