Interaction Between the Native Entomopathogenic Nematode Isolate Steinernema carpocapsae IRMoghan1 and the Insecticide Metaflumizone in the Control of the Tomato Leafminer, Phthorimaea (=Tuta) absoluta (Meyrick) (Lepidoptera: Gelechiidae) larvae

Articles in Press

Document Type : Research Paper

Authors

1 Biological Control Research Department, Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran,

2 Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran.

10.22059/ijpps.2026.411628.1007116

Abstract

Chemical control is generally the primary strategy to reduce damage caused by the tomato leaf miner, Phthorimaea absoluta (Lepidoptera: Gelechiidae). However, the implementation of alternative control approaches is essential. In the present study, the efficacy of the native entomopathogenic nematode isolate Steinernema carpocapsae IRMoghan1, metaflumizone, and their combined application was evaluated against larvae of P. absoluta within leaf mines. In a separate experiment, the effect of the insecticide on nematode survival was also assessed. According to the results, application of metaflumizone at 1000 ppm (98.3%) and the nematode alone (95%) resulted in the highest larval mortality, whereas the lowest mortality (52.5%) was observed at 250 ppm of metaflumizone. The combined application resulted in 86.7% pest mortality. Interaction analyses indicated an antagonistic interaction between the nematode and metaflumizone. Based on the compatibility assay, 24.28% mortality of infective juveniles was recorded after 72 h of exposure to the insecticide. According to IOBC/WPRS classification criteria, metaflumizone was categorized as harmless (Class 1) and compatible with S. carpocapsae IRMoghan1. The high mortality observed in the nematode treatment demonstrates its capacity to function effectively as a cruiser-type forager and to infect host larvae within leaf mines. One possible explanation for the observed antagonistic interaction, despite the classification of metaflumizone as harmless and compatible, is the already high level of mortality caused by the nematode alone, which may have limited the additive or synergistic effects in the combined treatment. Nevertheless, the underlying causes of the reduced efficacy of the nematode in combination treatments warrant further investigation.

Keywords

Iranian Journal of Plant Protection Science

Articles in Press, Accepted Manuscript
Available Online from 20 March 2026

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History

  • Receive Date: 20 February 2026
  • Revise Date: 15 March 2026
  • Accept Date: 20 March 2026

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