In 2001 was introduced in the State of Paraíba, the exotic pest Dactylopius opuntiae, commonly known as carmine cochineal, which already undertaken the cultivation of the giant cactus pear (Opuntia ficus-indica) in more than fifty cities. This study aimed to evaluate the infestation and dispersal speed of D. opuntiae at the field conditions, to establish a level of pest control. The research was performed in a field of giant cactus pear with twelve months cropped, artificially infested with the carmine cochineal in Lagoa Seca Experimental Station, Paraíba. The trial used was the completely randomized design (CRD) consisting of ten treatments (giant cactus pear plants) and ten repetitions (infested cladodes). Data were submitted to analysis of variance, using the ASSISTAT Application 7.5 Beta (2008). The results showed that ten colonies/cladodes caused infestation and a high dispersion of the insect. After 60 days the infestation and spread of colonies reached average value 171 colonies per plant. The dispersal of migrants nymphs are carried by wind from the cladodes to cladodes and plant to plant. From these results we can establish that the control level to carmine cochineal is less than 10 colonies/plant and the combat should be started immediately after detection of the first colonies of the pest in cactus pear crop.