Effect of Certain Barley Plant Varieties on Population Abundance of Some Piercing–Sucking Insects

The current work aimed to examine population abundance of some piercing-sucking-insects infesting different barely plant cultivars at Sharkia Governorate during 2022/23 and 2023/24 seasons. The insects were obtained by methods ofplant samples and sweeping net. These insects were: a)Aphids: Rhopalosiphum padi (Linnaeus),Rhaplosiphium maidis (Fitch), Schizaphis graminum (Rond.) and Sitobion avenae (Fabr); b) leafhoppers: Empoasca decedens (Paoli), E. decipiens (Paoli), Balclutha hortensis (Landb.) and Cicadulina chinai (Ghaui) and planthoppers: Sogatella vibix (Haupt) and S. furcifera (Horv.).Peak of R.padi, R.maidis, and S. graminum population occurred at the first week of March, while, S. avenaepeaked on the third week of March in barely fields. Population abundance of leafhoppers,E. decipiens , E.decedens, B. hortensiss and C.chinai showed a single peak at the end of February, whereas that of planthoppers,S. vibix and S. furcifera exhibited one peak during the third week of February.Barely varieties significantly affected the population abundance ofthe previously mentioned insects, with Giza 138 variety hosted the lowest mean number of insects, while the highest mean number of insects were found with Giza 123 variety. Chemical analysis revealed a positive relationship between protein and carbohydrate contents and insects attack, whereas an inverse relationship was obtained between pH values and insects attack.