Abstract
The tomato leafminer, Phthorimaea absoluta is a serious insect pest that threatens worldwide tomato production. In the present study, the compatibility of two native Iranian entomopathogenic nematode (EPN) isolates, Steinernema feltiae IRSardrood and Steinernema carpocapsae IRMoghan1, combined with flubendiamide, a convenient bio-rational insecticide, was measured using Galleria mellonella as a surrogate host. In a separate experiment, the efficacy of the EPNs, flubendiamide, and their combinations against P. absoluta larvae were evaluated at two relative humidity (RH) regimes. Mortality of EPN isolates treated with flubendiamide did not differ significantly during the first 72 h; however, a pronounced increase was observed for S. carpocapsae IRMoghan1 at day 7. Bioassay results against P. absoluta larvae revealed that S. carpocapsae IRMoghan1 (83.83%) and flubendiamide (89.17%) caused higher mean larval mortality than S. feltiae IRSardrood (73.43%). Steinernema feltiae IRSardrood caused the highest insect mortality (99%) at RH ≥ 90% and the lowest mortality (47.87%) at 70% RH. In conclusions, the high survival rates of the flubendiamide-treated EPNs up to 72 h and no adverse effect on their pathogenicity. The high efficacies of the nematodes and nematode-insecticide combinations against P. absoluta larvae, indicate the high compatibility of these nematodes with flubendiamide, which outlines a promising perspective for the inclusion of the native EPN isolates in the integrated control of P. absoluta.