The whitefly is the most annoying pest of any crop. It’s also one of the most difficult to get rid of. And yet, in order to control this pest, we have to know how to identify it. Whiteflies are small insects that feed on sap and plant juices.
The best way to tell if your plants have been invaded by whiteflies is to look at the leaves. If the leaves are small and yellow, then there’s a good chance that they have. If the leaves are large and yellow and the plant looks stunted, then it might be the case. If you see yellow mites or spider mites on the leaves, then you might also have whiteflies.
I'd look at the legs. Whiteflies have four pairs of legs (and there are several species that only have three pairs). If one pair is missing, it's a whitefly.