In Canada we see two main whitefly species: the Greenhouse Whitefly (Trialeurodes vaporariorum) and the Tobacco Whitefly (Bemisia tabaci). Both are widespread and both are broadly comparable in outline. They have 6 development stages: the egg, first, second, third, and fourth larval instars, and an adult insect.
Whiteflies damage plants by sucking out plant sap and leaving excreted honeydew behind. This can cause plant deformities, wilting leaves and leaf drop. Thus damaging the aesthetic value of certain crops. The excreted honeydew is also known to cause the growth of sooty moulds. This can make fruit unsaleable and cause a decrease in plant photosynthesis and transpiration. Another major issue is whiteflies are also known to transmit plant varieties.