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 (1x10¹ to 1x10⁷) 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 1x10⁷ 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 virusesthan E. cautella larvae. Further, the two insects were more susceptible to GV concentration than NPV concentrations. The corrected mortality percentages of E. cautella and P. interpunctella larvae were increased to 95.56 and 98.89% respectively after using mixture of LC₅₀s of two viruses compared to LC₅₀ 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.