The synergistic effects of entomopathogenic fungus Cordyceps javanica and parasitoid Tamarixia radiata in Asian citrus psyllid management

From the paper

Abstract

The Asian citrus psyllid (ACP), Diaphorina citri, is the primary insect vector of Candidatus Liberibacter asiaticus (CLas), which causes Huanglongbing (HLB) in citrus plants. Effective control of D. citri is crucial to preventing the spread of HLB in orchards. Biological control is a key component in Integrated Pest Management (IPM) programs aimed at reducing the use of synthetic chemical insecticides. This study evaluates the compatibility of the entomopathogenic fungus Cordyceps javanica (GZQ-1 strain) and the parasitoid Tamarixia radiata, dominant in controlling D. citri, to develop an effective pest management strategy and model for synergistic control. Our assessment showed that the survival rate of T. radiata was higher than that of D. citri when both were exposed to the same concentration of C. javanica, indicating higher toxicity of C. javanica to D. citri. However, the infected T. radiata exhibited reduced the search effect and parasitism. Five biological control methods were tested. Integrating interval period, pest mortality at different instar stages, and parasitoid population, the optimal strategy was determined to be releasing T. radiata within 6–12 days after spraying C. javanica during the initial flourishing period of the D. citri population. This comprehensive assessment of the safety and effectiveness of entomopathogenic fungi and natural enemies provides a basis for their synergistic application in IPM programs.