Determination of economics threshold levels for the stem borers (Scirpophaga sp.) and leaffolder (Cnaphalocrocis medinalis) of rice (Oryza sativa) in the Kallar tract of Punjab, Pakistan

Effective and economic suppression of insect pests in rice ecosystem by the judicial use of pesticides on the basis of economics threshold levels (ETL) is very essential. This study was conducted to determine the ETLs for the chemical control of rice stem borers, (Scirpophaga incertulas Wlk. & S. innotata Wlk.) and rice leaffolder (Cnaphalocrocis medinalis Gn.) in the traditional Basmati rice growing area the Kallar tract of the Punjab, Pakistan. On the basis of cost benefit ratio an action threshold of 5% dead-hearts (DH) and 3% folded leaves for stem borers and rice leaffolder, respectively were developed and use of insecticides to control these insects on need basis despite calendar based insecticides application was stressed.