Commercial flower crops in Colombia are largely grown within plastic greenhouses in the Sabana de Bogotá (Bogota Plateau). This study examined the abundance and flight activity of thrips in a chrysanthemum crop, estimated from plant samples, commercial yellow sticky traps, and non-commercial (self-crafted) yellow sticky tape traps installed in the crop. Frankliniella occidentalis was the dominant species present associated with all plant phenological stages. Abundance of larvae and adults was not evenly distributed throughout the greenhouse. An absolute method of plant sampling found 2.5 times more thrips larvae than the relative method of sampling plants by beating. For non-commercial traps, there was no difference in the number of thrips at different trap heights; however, traps facing the south-west caught significantly more thrips than traps facing north-west, north-east, and south-east. A moderate positive correlation was found between the number of thrips sampled on plants and the spatial location of the commercial sticky traps. The results found here provide a basis to design and standardize direct sampling methods for thrips on plants and indirect sampling using yellow sticky traps for monitoring and managing thrips in ornamental crops under plastic covers in Colombia.