We conducted investigations on seasonal population fluctuations of Serangium parcesetosum Sicard and citrus whitefly, Dialeurodes citri (Ashmead), in the East Mediterranean citrus orchards in Turkey from 1992 to 1995. Serangium parcesetosum and D. citri were sampled in two mandarin orchards at 2- to 3-wk intervals. Sooty-mold growth on honeydew excreted by the citrus whitefly on sampled trees also was evaluated as an indirect measure of the predator’s success. Serangium parcesetosum controlled D. citri populations effectively and prevented them from causing sooty-mold growth in the citrus groves in all 4 yr. It also fed and reproduced on brown soft scale, Coccus hesperidum L., another citrus pest, as an alternate host when D. citri populations were lower, and contributed to biological control, along with two other predators of coccoids, Chilocorus bipustulatus (L.) and Exochomus quadripustulatus L.