Abstract: Diaphorina citri Kuwayama is an important pest of citrus, navel oranges, and other members of Rutaceae family. Cheilomenes sexmaculata (Fabricius) is a common insect natural enemy in southern China. To assess the potential of C. sexmaculata to manage D. citri, the predatory functional response, search efficacy, and self-density interference response of the larvae (1^st and 4^th instar) and adults against various life stages of D. citri (early, late instar nymphs, and adults) were examined. Our findings demonstrated that the predatory functional response of Holling II is present in C. sexmaculata larvae and adults. The maximum daily predation amounts of the 1^st instar larvae of C. sexmaculata against the early and late instar nymphs of D. citri was 55.55 and 66.66 individuals, respectively. The maximum daily predation amounts of the 4^thinstar larvae of C. sexmaculata against the early, late instar nymphs and adults of D. citri was 500, 200 and 200 individuals, respectively. The maximum daily predation amount of the C. sexmaculata adults against early, late instar nymphs and adults of D. citri was 333.33, 250 and 125 individuals, respectively. With an increase in prey density, C. sexmaculata's ability to find D. citri reduced. With a rise in interference from the predator’s density at a constant D. citri density, C. sexmaculata’s predation effectiveness fell while its sharing competition intensity increased. This study offers a theoretical foundation for employing C. sexmaculata to control D. citri and Huanglongbing in the field.

Key words: Cheilomenes sexmaculata, Diaphorina citri, predation functional response, searching efficiency, self-density interference response