The frequency with which samples should be taken to monitor spider mites in cotton is dependent on the economic threshold and the rate at which an infestation develops. Later the start of an infestation, generally lesser the damage and therefore higher the economic threshold. The threshold for the strawberry spider mite, Tetranychus turkestani, is lower than for the Pacific spider mite, T. pacificus, and the two-spotted spider mite, T. urticae, because of the strawberry spider mite's apparent greater phytotoxicity. Lower the threshold, earlier and more likely that an economic threshold will be reached, but fewer the number of samples required during a season. Conversely, higher the threshold, greater the lead time for making management decisions, but generally greater the number of samples. A forecasting model has been developed, incorporating this information, which enables prediction of when next to sample. Preliminary analyses indicate that the forecasting model is able to predict when the mite infestation reaches a treatable level (within three days, up to five weeks prior to the economic threshold being reached. Use of the model as part of a spider mite management program could provide better timing of sprays and reduce sampling costs and unnecessary sprays.