Aphids are geographically and economically the most important group of phytophagous insects. They are responsible for various damage on cultivated plants. In our laboratory, we are interested in their ability to transmit phytoviruses such as Rhabdovirus, Cucumovirus, Potyvirus, and Caulimavirus which cause many crop diseases. The present work deals with the study of vectors as analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of internal transcribed spacer (ITS) regions. Electrophoresis of PCR-RFLP products using EcoRV, Alul and Dral restriction enzymes on 10% polyacrylamid gel reveals the coexistence of two different haplotypes in the same individual genome. This result seems to explain some features of aphid evolution.