Field Evaluation of some Insect Growth Regulators and Plant Originated Insecticides Against Sucking-Piercing Insects on Cucumber Plant and Their Side Effects on The Associated Predators

Commercial formulations of some botanical products azadirachtin, orange oil, and jojoba oil and insect growth regulators (IGRs) buprofezin, novaluron, and pyriproxyfen were evaluated as safe alternatives to synthetic insecticides imidacloprid and Pymetrozine against aphid Aphis gossypii Glover and whitefly Bemisia tabaci Gennadius in cucumber fields. Two experiments were conducted during 2021 and 2022 seasons, at El-hager area, Abou El-matameer, Al-Behira governorate. Side effects of the tested insecticides were also observed on the two predators lady beetle Coccinella septumpunctata Linnaeus and aphid lion Chrysoperla carnea Stephens. Imidacloprid significantly (P<0.05) achieved the highest initial and residual activity against aphid and whitefly in both seasons. The initial and residual reduction percentages of aphid were 94.5 and 98.9% in 2021 and 91.5 and 96.5% in 2022 as well as reduction percentages of whitefly was 85.7 and 92.4% in 2021 and 86.8 and 93.1% in 2022. Novaluron, buprofezin, pyriproxyfen and azadirachtin showed a moderate activity against whitefly and aphid in both seasons while orange and jojoba oils revealed the least reduction percentages. However, orange and jojoba oils have the least side effects on the aphid lion where the residual reduction percentages were 5.3 and 6.4% in 2021 and 6.4 and 7.3% in 2022. The least side effects on the lady beetle were exhibited by jojoba oil followed by orange oil and azadirachtin where the residual reduction percentages were 10.8, 14.7 and 15.6% in 2021 and 11.1, 16.1 and 15.3% in 2022, respectively. Pyriproxyfen, novaluron and buprofezin achieved more initial and residual toxicity on the two predators. On the other hand, imidacloprid and pymetrozine have the highest initial and residual side effects against the two predators. The reduction percentages of all treatments on the two predators were less than 50%. Therefore, all treatments were considered harmless according to the IOBC classification. The good selectivity feature of these formulated botanical products and IGRs, makes them good tools and suitable for integrated pest management (IPM) programs of sucking piercing insects.