EFFICACY OF ENTOMOPATHOGENIC FUNGI IN CONTROLLING THE POPULATION OF THE CITRUS MEALYBUG (PLANOCOCCUS CITRI RISSO)

The citrus mealybug (Planococcus citri Risso) is an invasive pest that has successfully acclimatized within the greenhouse complex of the Main Botanical Garden in Almaty, where it has become the primary phytophagous pest affecting citrus plants. Pest population control in enclosed environments presents considerable challenges due to the pest’s concealed lifestyle, the presence of a protective wax layer that enhances resistance to chemical treatments, the development of insecticide resistance, high reproductive rates, and the absence of effective natural population regulators. Entomopathogenic fungi represent a promising alternative to traditional control methods due to their environmental safety and targeted action against pest populations. This study aims to evaluate the effectiveness of entomopathogenic fungi in controlling the population of the citrus mealybug (Planococcus citri Risso). Strains of entomopathogenic fungi were provided by the laboratory of Al-Farabi Kazakh National University. The test organism was the citrus mealybug (Planococcus citri Risso). Virulence screening experiments utilized different conidial concentrations of entomopathogenic fungi: 1×106, 1×107 and 1×108 spores/ml. Biological efficacy was assessed using Abbott’s formula. Experimental studies conducted in 2024 demonstrated that entomopathogenic fungi of the genus Beauveria exhibited low efficacy in the biological control of the citrus mealybug. The maximum mortality rate of the pest reached 58% at a concentration of 1×108 spores/ml, while at 1×106 spores/ml, this rate was 30%. The mortality dynamics indicated an increase during the first nine days, followed by stabilization or decline on the eleventh day. Despite the widespread use of Beauveria bassiana in pest population regulation, its effectiveness in this study was lower than expected, highlighting the need for more virulent fungal strains for the control of the citrus mealybug (Planococcus citri Risso).