Cabbage Whitefly Control
Identifying a Cabbage Whitefly Infestation
You can recognize the presence of cabbage whiteflies by moldy looking spots on the leaves of plants. If you see moldy spots like this, then look underneath the leaves. If you see a little white cloud of insects fly up, then you know that you have a whitefly problem.
The first step is to spray the infected plants with diluted liquid dish soap. This will often be enough to rid the plants of whiteflies. If that does not work, then the next step to try is Neem oil. Make sure to spray the entire plant with the oil, as the whitefly has to come in direct contact with the oil in order for it to be effective.
If the organic treatment does not work, then a more aggressive chemical approach can be attempted. An insecticide containing permethrin can be used. However, be very cautious with this chemical. Be sure to follow the directions on the package to the letter. Also, be sure to leave at least a week between an application of permethrin and vegetable harvest.
One of the most effective and satisfying ways to fight a cabbage whitefly infestation is to introduce parasitic predator wasps into the garden. Encarsia formosa is a tiny wasp that does not sting humans. It will attach itself to a whitefly, feed on the body, and then deposit its eggs into the whitefly's carcass. The eggs will then hatch and seek out any whiteflies bold enough to remain.