Insects in a commercial poinsettia (Euphorbia pulcherrima) greenhouse were monitored with yellow sticky card (YC) traps and YC equipped with 530-nm lime green light-emitting diodes (LED-YC) traps from 3 June to 25 Nov. 2002. Pest insects were: dark-winged fungus gnat (Bradysia coprophila), sweet potato whitefly (Bemisia tabaci) biotype B (= B. argentifolii), western flower thrips (Frankliniella occidentalis) and leafhopper (Empoasca sp.). Natural enemies were: minute pirate bug (Orius tristicolor), parasitic wasps (Hymenoptera), and rove beetles (Staphylinidae). Over the 24 weeks of the experiment, LED-YC traps captured more dark-winged fungus gnats, sweet potato whiteflies, leafhoppers, and rove beetles compared with YC traps. Capture of western flower thrips, minute pirate bugs, and parasitic wasps were not significantly increased on the YC traps equipped with LEDs. The results indicate that the LED-YC traps attract three major pest insects in poinsettia greenhouses and do not catch more beneficial, minute pirate bugs and parasitic wasps, but may catch significant number of rove beetles. The results suggest that LED-YC traps may be useful to monitor and reduce pest populations in greenhouses.