Biological Control of Two Date Fruit Insect Pests Using Entomopathogenic Viruses

Abstract

The date palm is one of most important fruits in Middle East. Date fruits are exposed to infestation by many insect pests like Ephestia cautella (Walker) and Plodia interpunctella (Hübner) which decrease their quantity and quality. This study aimed to evaluate efficiency of two viruses (NPV and GV) on mentioned these insects. Seven concentrations of each virus were tested (1x10 1 to 1x10 7 ) against these two insects at various durations: 5, 7, and 10 days. Results showed that corrected larval mortality% of E. cautella and P. interpunctella increased by increasing viruses concentrations and exposed durations with highest percentages were 54.44 and 73.33% for E. cautella and P. interpunctella larvae respectively compared with control after treating with NPV virus 1x10 7 for 10 days. While these were 74.33 and 100% for E. cautella and P. interpunctella respectively in case of GV virus compared with control. Data obtained revealed that P. interpunctella larvae were more susceptible to tested viruses than E. cautella larvae. Further, the two insects were more susceptible to GV concentration than NPV concentrations. The corrected mortality percentages of E. and P. interpunctella larvae were increased to 95.56 and 98.89% respectively after using mixture of LC 50 s of two viruses compared to LC 50 of each virus separately. In addition, both viruses exhibited no-effect on tested chemical contents of date’s fruits. As a conclusion, combination of both viruses increased their efficacy against E. cautella and P. interpunctella and this has to be considered in biocontrol programs of both insect pests.