The purpose of this research was to evaluate the naturally occurring biological control of spider mites. We focused on the two groups: omnivorous western flower thrips, Frankliniella occidentalis and generalist predatory bugs (specifically Orius tristicolor and Geocoris spp.). We used multiple approaches; including field enclosures and insecticide manipulations, to manipulate predator abundance. We found that western flower thrips were successful in substantially reducing spider mite population growth during the early season, and this, in turn, led to greater seed cotton yields at the end of the season. Also, we observed no yield losses caused from early-season plant feeding by western flower thrips. Generalist predators, especially O. tristicolor and Geocoris spp., were very effective at suppressing mites. For three different field seasons, we found that predators suppressed spider mite populations to levels 76 - 99 percent below those observed where generalist predator abundance had been reduced. Furthermore, we observed high levels of suppression using multiple techniques to manipulate predators: levels of spider mite suppression were similar in cage and insecticide manipulation experiments. Finally, we found that generalist predators suppressed mites over a fairly wide range of initial spider mite densities. These findings demonstrate the importance of conserving naturally occurring predators of spider mite control; efforts should be made to find replacements for broad-spectrum insecticides that frequently decimate generalist predator populations.