A monitoring method relating adult thrips populations to tomato spotted wilt virus (TSWV) epidemiology in field-grown tomatoes was tested. Predatory bugs and thrips were counted on leaflets, flower clusters, and blue and transparent sticky traps in commercial fields. The percentage of plants with virus symptoms was determined. Adult thrips were more abundant in flower clusters than on leaflets. Predators were also detected in the flowers. Sampling of flowers was less time-consuming and easier than sampling leaflets. Blue and transparent sticky traps showed the same pattern of thrips catches. Both are good indicators of immigrating thrips. No relation was found between trap catches and thrips density on plants. More data must be obtained to assess the effectiveness of each method to explain TSWV incidence.