Watch out for all life stages of greenhouse whiteflies

Whitefly eggs and nymphs are often first introduced in the greenhouse via propagation material, and they can be hard to see unless you know what you're looking for, Bográn says. Adult whiteflies can also enter the greenhouse through open vents.

"It's best to keep them out early by inspecting or treating cuttings when they arrive," Bográn says. "For adults, installing screens can help prevent them from entering the greenhouse."

Source: Greenhouse Grower

Source: Greenhouse Grower