Citrus blackfly (CBF) Aleurocanthus woglumi Ashby, is a serious citrus pest of South Asian origin it was detected in Mexico in 1935 and controlled by 1953. It damages citrus by sucking nutrients from foliage, which weakens the plants. CBF excrete honeydew on which sooty molds develop; sooty molds can severely impair leaf respiration and photosynthesis. The combined effects on the tree of blackfly feeding and the associated sooty mold can result un serious fruit yield reductions. Blackfly infestations are encountered today in the state of Tamaulipas, Nuevo Leon, San Luis Potosi and Veracruz, the main citrus producers in Mexico. The main objective of this study was to know the distribution and CBF infestation level and parasitization in the indicated states of Mexico. CBF presence has been confirmed in 3304 hectares, leaf samples from these groves showed infestation from 65 to 90 % and dissection of CBF immature indicated parasitization from the introduced parasitoid Encarsia perlexa ranged from 90 to 100 %.