Whiteflies (Aleyrodidae) is small group of insects (Insecta) that comprises around 1500 species from 160 genera. Whiteflies damage important cultivated and ornamental plants by sucking plants juice. Most of the species are from tropical area, in our region they are the most common in greenhouses. Because worldwide transport, whiteflies become invasive all around the world. The identification of whiteflies species in adult stage is problematic. Morphological differentiation of pupae is one of the better methods for determining identity of species, but it may vary depending on the host plant on which they develop which can lead to misidentifications and erroneous naming of new species. The application of genetic diagnostics under the umbrella of classical taxonomy was imperative for successful development and delivery of the biological control program, phylogenetics and plans for biological control. The most common modern techniques for whiteflies determination are computer programs for photography analysis, molecular methods with DNA isolation and sequencing.