Abstract

Ethiopia is the only country in Sub-Saharan Africa where smallholder wheat production meets more than 70% of the national consumption demand. Russian wheat aphid (RWA; Diuraphis noxia (Mordvilko) (Hemiptera: Aphididae) is one of the major insect pests of wheat throughout the world including in Ethiopia. Wheat yield loss due to RWA damage in Ethiopia was estimated to be 70%.  Therefore, the present study was carried out to determine the effect of integrating the potentials of the plant extracts of Neem, Azadirachta indica L. (leaf and seed) and the Entomopathogenic fungi (EPF); Beauveria bassiana and Metarhizium anisopliae against the RWA. After 7 days of applications; the combined mixture of B. bassiana with M. anisopliae caused the maximum loss (73.4%) of aphids, while the combination of Neem leaf with seed extracts recorded the least (57.82%) abundance of aphids, which were negatively affected by single and combined treatments. The lowest abundance was recorded when the aphid was treated by the combination of both B. bassiana and M. anisopliae as well as the combined mixture of Neem leaf and seed extracts. The results indicated that bio-pesticides, based on entomopathogens and botanical extracts (Neem) can be the best replacements for synthetic chemicals and caused significant reduction in survival and abundance of RWA. Therefore, they could be used as promising natural alternatives to synthetic insecticides against RWA in Ethiopia.

Key words: Russian wheat aphid, Diuraphis noxia, Beauveria bassiana, Metarhizium anisopliae, Neem, efficacy.