Compatibility of two native isolates of entomopathogenic nematodes, Steinernema carpocapsae IRMoghan1 and Steinernema feltiae with bio-rational insecticide Flubendiamide

One of the important aspects of the field application of entomopathogenic nematodes is their compatibility with common chemicals in agricultural systems. In this research, the effect of bio-rational insecticide, flubendiamide on the survival and pathogenicity of native entomopathogenic nematode isolates, Steinernema carpocapsae IRMoghan1 and Steinernema feltiae was evaluated. For the survival experiment, nematode suspensions (500 IJml-1) were prepared in 150 ml recommended dose of flubendiamide (25 ppm) and at different time intervals (24, 48 and 72 hours and seven days) survival percentages of the nematodes were recorded. For the pathogenicity experiment, the nematodes that were exposed to the insecticide were used in the bioassay against Galleria mellonella (concentration of 150 IJ Larvae-1) and the mortality of the insects was recorded after 72 hours. Based on the results of variance analysis, S. carpocapsae IRMoghan1 showed higher mortality compared to S. feltiae due to flubendiamide treatment (P ≤ 0.01). Also, after 24 hours and 48 hours of treatment with flubendiamide, the lowest percentage of mortality and seven days after the treatment, the highest mortality rate of the nematodes were observed (P ≤ 0.01). Statistical analysis of the bioassay results of nematodes recovered from different time treatments with flubendiamide insecticide on G. mellonella larvae showed no significant difference between two nematode isolates (p˃0.05). Flubendiamide was considered compatible with and harmless (Class 1) to both native isolates according to IOBC/WPRS. Compatibility of the native isolates is a valuable characteristic for application development of EPNs in the country.