How effective is lambda-cyhalothrin against imported cabbageworm (Pieris rapae) on cruciferous vegetables? The key lies in application timing.

Pieris rapae (imported cabbageworm) is a common pest on cruciferous vegetables, primarily active on the undersides of leaves and tender shoots. When population densities are high, leaves are chewed and plant vigor is reduced. For effective control of Pieris rapae on cruciferous vegetables, early intervention and accurate targeting of the affected plant parts are essential—lambda-cyhalothrin 25 g/L EC (emulsifiable concentrate) is registered for use against Pieris rapae on cruciferous vegetables.

Diamondback moth larvae are most susceptible to control during the early instar 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 heart leaves or the ear, so as to thoroughly cover the critical target sites.

Lambda-cyhalothrin 25 g/L EC (Emulsifiable Concentrate), Registration No. PD20083265 (subject to the actual label). Applied to control imported cabbageworm (Pieris rapae) on cruciferous vegetables, and also covers citrus leafminer (Phyllocnistis citrella) on citrus trees. Spray at a rate of 20–30 mL per mu with water. Apply during the early larval stages, and re-apply at intervals of 7–10 days depending on pest pressure. Observe the pre-harvest interval (PHI).

Ensure thorough spray coverage of all primary infection sites, including the undersides of leaves and tender shoots. Rotate fungicides with different modes of action to delay resistance development. Apply strictly according to the pre-harvest interval and avoid application during bee activity periods. Always follow the product label for specific instructions.