The Role of Entomopathogenic Fungus, Beauveria bassiana (Bals.) Vuill. in Reducing Population Densities of Refugee Insect Pests to Dry Okra Pods During Winter

Document Type : Original Article


1 Plant Protection Department, Faculty of Agriculture, Tanta University, Egypt

2 Plant Protection Research Institute, Agricultural Research Center, Egypt


The present work was carried out during two successive seasons, being 2019/20 and 2020/21 in three locations in Gharbia governorate to explain the role of entomopathogenic fungi (EPF) in decreasing insect pest populations inhabiting okra dry pods during the winter period. Three insect pest species were found in the okra dry pods: the cotton seed bug, Oxycarenus hyalinipennis (Costa) (Hemiptera: Lygaeidae), the cotton pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) and the cotton spiny bollworm, Earias insulana (Boisd.) (Noctuidae: Lepidoptera). The EPF, Beauveria bassiana (Bals.) Vuill. was isolated from the 3 insect species in the winter months. The seasonal fungal incidence percentages were 3.04 and 10.73% in nymphs and adults of O. hyalinipennis, respectively in the first season and were 13.53 and 16.53% in the second one. The seasonal fungal incidence percentages on P. gossypiella larvae were 4.64 and 7.96% for the two seasons, respectively. Natural mortality with the fungus ranged from 4.32 to 14.16 and 4.32 to 20.63% in the two seasons, respectively. Whilst the seasonal fungal incidence percentage on E. insulana larvae were 6.02 and 5.23 % for the first and second seasons and the fungus was isolated for one time in each season. Results explained and approved the role of EPF as natural mortality factors against insect pest species in their winter microhabitats in Egypt. Accordingly, it encourages biological control advocates to utilize such natural enemies as biological control agents.