Efficacy of Six Aqueous Plant Extracts and Three Commercial Entomopathogenic Fungi Against the Corn Ground Beetle Larvae, Zabrus tenebrioides, Under Laboratory Conditions

Khidr, S.K. and S.M. Khalil. 2024. Efficacy of Six Aqueous Plant Extracts and Three Commercial Entomopathogenic Fungi Against the Corn Ground Beetle Larvae, Zabrus tenebrioides, Under Laboratory Conditions. Arab Journal of Plant Protection, 42(1): 120-127. https://doi.org/10.22268/AJPP-001221 The efficacy of aqueous plant extracts and entomopathogenic fungi as an alternative to conventional pesticides to manage the corn ground beetle, Zabrus tenebrioides on wheat were investigated. The results obtained indicated that maximum mortality (100%) was achieved by both Eucalyptus, Eucalyptus globulus and Thuja, Platycladus orientalis aqueous extracts 5 days after treatment, followed by rosemary, Salvia rosmarinus and Neem, Melia azedarach seven and eight days, after treatment, respectively. In addition, the efficacy of aqueous plant extract types tested on the larval stage was influenced by the concentration applied, and higher doses were more toxic and caused more mortality in the insect population. On the other hand, the larvae were more resistant to the tested fungal bioinsecticides than the botanical insecticides utilized in the test. Beauveria bassiana and Trichoderma harzianum achieved maximum and minimum mortality rate of 100 and 71.7%, respectively, eight days after treatment and the mortality rate didn’t differ significantly among the tested concentrations. The LC50 value of the aforementioned entomopathogenic fungi was 119960.37 and 566168.82 conidia/ml, respectively, during the last day of exposure. The positive control (Alphacypermethrin 10%) produced the highest mortality of 100% on the third day of exposure, whereas the negative control (distilled water) gave minimum mortality in all experiments. Keywords: LC50, Beauveria bassiana, Metarhizium anisopliae, Eucalyptus globulus, Platyclaudus orientalis, control.