Essential oils vs. Synthetic insecticides: Evaluating field performance, profitability, and environmental impact in Tuta absoluta (Lepidoptera: Gelechiidae) management

This study evaluated the efficacy, environmental impact, and economic feasibility of essential oils (EOs) as biopesticides for controlling Tuta absoluta (tomato leaf miner). Laboratory bioassays were conducted to assess the larvicidal effects of four essential oils: peppermint, clove, basil, and lemongrass. Among them, peppermint EO demonstrated the highest potency (LC₅₀: 59.79 ppm, LC₉₀: 2431.24 ppm) and the fastest action (LT₅₀: 9.83 hours, LT₉₀: 22.37 hours). Given its strong larvicidal performance, peppermint EO was further evaluated under field conditions. Field trials were conducted on two tomato farms using a completely randomized design (CRD). Each site (S1 and S2) consisted of 18 plots, divided into three treatments: TEO (essential oil), TIS (synthetic pesticide), and T0 (untreated control), with five replicates per treatment. Foliar and fruit damage assessments revealed that in S1, TEO reduced foliar damage from 8.82 ± 0.91 (T0) to 4.62 ± 0.67 by the second observation and from 34.86 ± 8.54 (T0) to 21.42 ± 5.19 by the sixth observation. Fruit damage was also significantly reduced, from 38.16 ± 7.32 (T0) to 10.36 ± 2.35 in S1 and from 44.95 ± 8.84 (T0) to 12.70 ± 1.87 in S2. Economic analysis, based on profit percentage from yield, showed that TEO achieved an average profit rate of 26%, significantly higher than T0 (1%) and comparable to TIS (30%). Additionally, the Environmental Impact Quotient Field Use Rating (EIQ-FUR) was calculated to assess environmental impact. TEO demonstrated a low environmental footprint, with an FUR of 1.3 compared to 29.31 for chemical pesticides. These findings highlight the potential of peppermint EO as a safer, environmentally friendly alternative to synthetic insecticides. Further studies are needed to optimize formulation and application strategies.