Tomatoes are the most familiar and the most common greenhouse vegetable crop in Turkey, as well as worldwide. Main whitefly species problematic in the greenhouses, where tomatoes grown primarily, is Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) in Mediterranean Region of Turkey. Serangium parcesetosum Sicard (Coleoptera: Coccinellidae) is proved as a coccinellid predator of B. tabaci and a voracious feeder by several studies. The hypothesis "the outcome of a biological control program is determined by the initial pest to predator ratio" was examined on caged tomato in greenhouses. The current study showed the influence of initial whitefly density on the whitefly population growth rate, which was independent of the absence or presence of S. parcesetosum (P> 0.05) for the whitefly density × predator release interaction). No significant differences in whitefly suppression from S. parcesetosum predation were monitored between the two initial whitefly densities in both years. The density of the pest was reduced by S. parcesetosum in high and moderate initial whitefly density cages 2-3 weeks after releasing the ladybird beetles. During the experiment, copulating adults, larvae, and pupae of the predatory ladybird beetle were observed in both predator-releasing cages. These results indicated that S. parcesetosum can survive and reproduce on tomato plants in greenhouse production during the spring months in Mediterraenean region of Turkey.