What is the efficacy of Yili against cotton bollworm in cotton? The key lies in the timing of application.

Cotton bollworm (*Helicoverpa armigera*) is a common pest on cotton, frequently active on the undersides of leaves and tender shoots. When populations are high, leaves are chewed and plant vigor is reduced. Timely intervention and precise targeting of the affected plant parts are key to controlling cotton bollworm—Yili 30% Acephate EC is registered for use against cotton bollworm on cotton.

Helicoverpa armigera is most susceptible and easiest to control during the early instar larval stages, when resistance is low. Once the population surges and leaf rolling occurs, spraying becomes both costly and difficult to manage. Before application, determine whether the larvae are on the adaxial or abaxial leaf surface, and whether they are in the whorl or the ear, so that the target sites can be thoroughly covered with the spray.

Acephate 30% EC (Emulsifiable Concentrate), Registration No. PD20101212 (subject to the actual label). Applied for cotton bollworm (Helicoverpa armigera) on cotton, and also covers rice planthoppers (Nilaparvata lugens and Sogatella furcifera) on rice, at a dosage of 150–170 mL per mu (667 m²) with water spray. Apply during the early larval stage, and re-apply at intervals of 7–10 days depending on pest pressure. Observe the pre-harvest interval (PHI) as specified.

Ensure thorough spray coverage of all primary infestation sites, including the undersides of leaves and tender shoots. For acephate EC, rotate with insecticides of different modes of action to delay resistance development; adhere to the pre-harvest interval and avoid application during bee foraging periods. Always follow the label instructions.