The whitefly belongs to the same group of insects as aphids and scales. This pest not only causes damage by feeding, but may also transmit plant viruses. Whiteflies are capable of rapid reproduction once summer heat arrives, intensifying infestations.
What It Looks Like
This tiny, white insect is about 1/20 inch long. Mature adults are able to fly. They congregate on the undersides of leaves and swarm in clouds when the infested plant is disturbed.
The Threat It Poses
The whitefly feeds on more than 500 species of host plants. Common targets include ornamental plants, houseplants, hibiscus, coleus, fuchsia, sweet potato (edible and ornamental), tomato, grape, citrus and squash-family plants.
Whiteflies suck juices from plants, leading to wilting and stunted growth. Severe infestations cause leaf yellowing and leaf drop. Leaves of squash-family plants will turn silvery. Whiteflies also excrete honeydew, a sweet, sticky substance that attracts wasps, ants and bees and can serve as a medium on which black fungus can grow.
Currently, the whitefly is not rated as a pest with quarantine status. However, areas with crops grown in spring and summer, such as Texas, and areas with crops grown in winter, such as Florida and California, or over large acreages, are susceptible to very large whitefly populations. In warmer climates, whiteflies can be present year round. Higher populations can occur in warmer months.
How You Can Help
Minimize insect infestations with these suggestions from the United States Department of Agriculture Systematic Entomology Laboratory:
- Visually inspect your plants.
- Provide ideal growing conditions. Nothing keeps insects at bay like a healthy plant.
- Destroy old crop residues that harbor whitefly infestations unless large numbers of natural enemies of whitefly are detected. Destroy all crop residues infected with virus.
- Plant resistant varieties where available.
- Plant earlier in the spring and late in the fall to avoid high infestations late in the season and use short-season varieties.
- Avoid planting next to crops infested with whitefly and avoid carry-over from infested plant material.
- Delay planting fall vegetables until whitefly migration has diminished: Use physical barriers during heavy migration or plant tolerant crops during these periods.
- Adopt spraying methods that improve coverage, especially underneath leaves.
Treating Your Trees
Use foliar or systemic insecticides to protect your plants against whiteflies. Check with your local Cooperative Extension office and follow all label instructions.
Products that kill or prevent this pest