Why do striped stem borers in rice never seem to be fully controlled? With chlorpyrifos–bisultap, timing is everything—target the early instar larvae to save on pesticide use.

Rice yellow stem borer (*Scirpophaga incertulas*) is a common pest on rice, frequently active on the abaxial leaf surface and tender shoots. When population densities are high, leaves are chewed and plant vigor is reduced. For effective control of rice yellow stem borer, early intervention and precise targeting of the affected plant parts are critical—Pyridaphenthion-cartap 35% WP is registered for use against rice yellow stem borer on rice.

The striped stem borer (Chilo suppressalis) exhibits low resistance and is easier to control during the early instar larval stage. Once the pest population surges and leaf rolling occurs, subsequent insecticide applications become both costly and difficult to manage. Before spraying, carefully identify whether the larvae are located on the adaxial or abaxial leaf surface, and whether they are infesting the whorl or the panicle, so as to thoroughly penetrate the critical target sites.

Bisultap 35% WP (Bisultap·Monosultap Wettable Powder), Registration No. PD20040601 (subject to the actual label). Used for the control of rice yellow stem borer (*Scirpophaga incertulas*), also covering rice striped stem borer (*Chilo suppressalis*) and rice leaf roller (*Cnaphalocrocis medinalis*), at a dosage of 86–143 g per mu (667 m²) diluted with water for foliar spray. Apply during the early larval stage, and re-apply at intervals of 7–10 days depending on pest incidence. Observe the pre-harvest safety interval.

Ensure thorough spray coverage of all primary infestation sites, including the undersides of leaves and tender shoots. For pyridaphenthion–cartap wettable powder, rotate with products 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.