Smart Detection System for Monitoring of <i>Helicoverpa armigera</i> (Hübner) (Lepidoptera: Noctuidae) Population Fluctuations and Determination of Economic Injury Level in Tomato Fields

Effective pest management relies on accurate estimation of population density, damage assessment, and determination of the economic injury level (EIL). The tomato fruit borer, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is a major pest of tomato and many other crops worldwide, causing substantial yield losses and increasing production costs. This study aimed to design and construct a smart detection system (SDS) for monitoring population fluctuations of H. armigera in tomato fields and to calculate the EIL under Iranian environmental conditions. To compare different monitoring approaches, the cultivated area was divided into three treatment groups: control (no intervention), conventional larval scouting, and SDS‐based monitoring. Continuous field data recorded by the SDS throughout the growing season revealed that adult activity extended from June 27 to September 8, with four distinct generations. Peak attraction to the SDS occurred between 1:00 AM and 3:00 AM, confirming a distinct nocturnal activity pattern. Significant differences in average yield were observed among the three treatments, with the highest yield recorded in the SDS‐based treatment and the lowest in the untreated control. Regression analysis demonstrated a significant negative relationship between larval density and yield, with each additional larva per plant reducing yield by approximately 556 g. Depending on market value (low, medium, or high), EIL values ranged from 0.33 to 0.49 larvae per plant in 2023 and from 0.24 to 0.46 larvae per plant in 2024. The calculated economic thresholds (ETs) ranged from 0.20 to 0.39 larvae per plant across both years. Monitoring population fluctuations and determining EIL for H. armigera can assist farmers in optimizing spray timing and reducing indiscriminate pesticide use. Overall, the SDS offers a promising tool for integrated pest management (IPM) programs, enabling more precise, timely, and environmentally responsible control decisions.