Sequential sampling plans were developed using yellow sticky traps to capture adults of Liriomyza trtfolii (Burgess)(Diptera: Agromyzidae) in chrysanthemum greenhouses. Two types of yellow traps were employed: a large plastic trap (30.5 by 30.5 cm) with a maximum percentage of reflectance of 81 at 575 nm and a small fluorescent cardboard trap (11.4 by 14.0 cm) with a maximum percent reflectance of 156 at 575 nm. Separate sampling plans were developed for each trap. Trapping at several locations from 1981 to 1983 revealed that the variance/mean relationship of catches was consistent from year to year, location to location, and trap type to trap type. A requirement is that traps must be positioned only over homogeneous blocks of chrysanthemums (i.e., chrysanthemums planted less than 30 days apart). Standard formulae (Taylor’s power law and Iwao’s patchiness regression) were fit to the data. Iwao’s patchiness regression best described the variance/mean relationship ( R2 = 99.9 and 97.4 for small and large traps, respectively). Stoplines were then generated with a fixed level of precision of 0.25. Validation of the sampling plan for large traps in 1982 demonstrated that only 18% of the traps throughout the growing season need be counted to achieve the fixed level of precision.