Sweet Potato Whitefly, also known as the Silverleaf Whitefly, is resistant to many pesticides and it is an economically important pest in Florida, the Gulf Coast states, Arizona, and California. It is aggressively adaptable and has a very wide host range – more than 500 plants. This whitefly has been known to attack crops such as avocado, beans, broccoli, cabbage, chrysanthemum, cotton, poinsettia, peas, peppers, pumpkin, radish, squash, sweet potato, tomatoes, and watermelon.
Aside from the general damage this whitefly inflicts by sucking out the sap from the plant leaves, it is also a vector for plant pathogenic viruses. They introduce squash silverleaf disorder, lettuce leaf yellow, stem blanching, carrot light root, pepper streak, Brassica white stem, chlorosis of new foliage, and Tomato Yellowleaf Curl virus.
The adult moth is tiny, about 6/10" long with a wingspan of about 1/10" and their yellowish wings and bodies are covered with fine, white, waxy particles. They often leave behind a sugary, sticky substance known as honeydew. The honeydew is the perfect breeding ground for black sooty mold.
Control of this whitefly requires a well-defined IPM program that includes Cultural Controls, Biological Controls and Organic Control Methods.
Critical steps in Cultural Control of this pest are:
- Keep a clean and sanitary planting area.
- Rogue out any infested plants and destroy – do not compost.
- Remove any crop residue after harvest.
- Plant short cycle crops to produce output in the shortest time possible.
- Manage irrigation and nitrogen fertilizing properly. DO NOT over-water or over-fertilize as this produces a flush of green growth that this whitefly loves.
- Use fine meshed screens in greenhouses to keep the whitefly out.
- Use yellow or aluminum mulch covers between planting rows.
- Encarsia Formosa
- The Sweet Potato Whitefly Predator, Delphastus catalinae
- Eretmocerus eremicus
- Green Lacewing
- Minute Pirate Bugs
- Insecticidal Soaps can be used as a quick knockdown spray prior to releasing beneficial insects.
- Horticultural Oils - Check labels to ensure that the individual product you choose is labelled for use on your specific plant(s).