Evaluation the effectiveness of entomopathogenic nematodes with the biopesticide Spinosad against the pupa of Cucurbit lesser fruit fly Dacus ciliatus(Loew),(Diptera: Tephritidae) under laboratory conditions

Abstract

The study was conducted during the period from September 2022 to October 2023 in the laboratories of the College of Education, University of Samarra, to the evaluate the effectiveness of four isolates of the entomopathogenic nematodes: the local  Heterorhabditis indica, the imported Heterorhabditis bacteriophora and the local and imported  Steinernema carpocapsea, with the biopesticide Spinosad at multiple concentration against the pupa of the Cucurbit fruit fly D. ciliatus, as a safe control tool to reduce chemical environmental risks, by using concentrations of 50,100 and 150 IJS/pupa, the results showed the superiority of the local isolate  Heterorhabditis indica by achieving the highest pupa killing rates of 53.3% at the concentration 150 IJS /pupa, followed by the local isolate S. carpocapsae  with the killing rate of 50% in the, while the two imparted isolate H. bacteriophora and S.carpocapsea achieved alower of kills for pupa 46.7%repectively, at the same concentration. The results also showed that the process of synergizing entomopathogenic nematode isolates with the pesticide leads to achieving high killing rates compared to applying the isolates alone, as the killing rates for H. indica and H. bacteriophora when treating virgin with a mixture of the isolates and the local a and imported isolates S. carpocapsae reached 83.3, 80, 76.7 and 60% respectively, treating pupae with a mixture of entomopathogenic nematodes and the biopesticide resulted in significantly higher rates of killing pupa, and the effect of the combination of nematodes and Spinosad increased gradually with increasing concentrations compared to treatment with nematodes alone. The results of the current study also showed that a combination of entomopathogenic nematodes and the pesticide Spinosad can successfully be applied in insect pest control programs.