Whiteflies are a group of tiny flying insects that can be major pests of winter vegetables like cabbage, broccoli, and collards, as well as many ornamental plants.
These light-colored insects use their piercing-sucking mouthparts to feed on the juices in a plant’s leaves, causing the top sides of the leaves to become pale or spotted.
They also excrete a sticky honeydew that can lead to sooty mold infestations.
If left unaddressed, whitefly populations will continue to grow and cause the plants to decline.
A good strategy is to treat whitefly infestations with a horticultural oil spray. Take care to spray the undersides of the leaves as well as the tops, and remember it may take a few treatments to get the pest populations in check.