The objective of this research was to study the populational behavior of Tetranychus urticae Koch, feeding on cotton plants (Gossypium hirsutum L.) submitted to the application of deltamethrin and the phenoxy-benzoic-acid, the main decomposition product of deltamethrin and several other pyretroyds. The insecticide was exposed to fotodecomposition for two, eight and 15 days, before sprayed on cotton plants. The reproduction rate of the T. urticae increased after cotton plants were sprayed with deltamethrin and phenoxi-benzoic-acid.
Pyrethroyds insecticides; cotton plants; mite
