Sweet Potato Whitefly or Silverleaf Whitefly (Bemisia tabaci) is an insect in the Whitefly (Aleyrodidae) family. This group of destructive pests primarily attacks cotton and vegetables. The sweet potato whitefly thrives in tropical and subtropical conditions. It is tiny, just about 3 mm, looks like a small white triangle and inhabits the underside of the plants it attacks. The insect harms plants by feeding on the plant sap, leaving it weakened.
How to eliminate sweet potato whitefly using organic methods
1. Use the combination of jet water & insecticidal soap
Blasting the leaves with a jet of water is effective in reducing the severity of infestation. Combining hosing with spraying of the leaves with insecticidal soap can help eradicate the insects.
2. Inspect seedlings from the nursery before transplanting
The vast majority of sweet potato whitefly infestations arise from seedlings imported from nurseries. Therefore, ensure you inspect all planting material before allowing then into the greenhouse. You should bag all infected planting securely before putting them in the garbage dump.
3, Use predatory pests
Encarsia Formosa, a species of wasp that is commercially available from vendors of biological pest control agents, is an effective parasitoid of the sweet potato whitefly. One wasp can eliminate up to 100 whiteflies, which makes this method very effective. You can buy these wasps and release them into your greenhouse.
Delphastus pusillus, a small ladybird beetle, is just as effective. Like Encarsia Formosa, this beetle is available from biological pest control outlets.
4. Clean the greenhouse
Ensure you clean your greenhouse in between growing seasons. Cleaning should be thorough and cover the entire breadth of the greenhouse, including the workbenches. For this reason, ensure the greenhouse kits you purchase are easy to clean when necessary.
5. Plant a diversified garden
Diversified gardens that have several species of flowering plants can help contain whitefly infestations, because such gardens provide appropriate conditions that allow natural predators such as lacewing larvae and ladybird beetles to thrive.