author(s)
Zunnu Raen Akhtar, Aqsa Noreen, Ahmad Ali Anjum, Zain Saeed, Shanza Ahmed, Jawad Khalid, Muhammad Abubakar Salman, Hasooba Hira and Arbab Ahsan

abstract
Maize is one of the high yielding and most grown cereal crop in the world. Maize stem borer Chilo partellus is most destructive pest of maize in fields of Pakistan. Cypermethrin from pyrethroids group of insecticides is used to control Chilo partellus. Experiment was conducted to observe the percent damage of Chilo partellus using cypermethrin (synthetic pyrethroid). Percent damage of Chilo partellus was observed at low, standard and high concentrations. Replications used in this experiment were ten for each treatment. Observations were recorded after time interval on different dates to observe if resistance was found in stem borers and to observe the percent damage. Results found that low damage percentage was observed on high sprayed concentration fields, while medium percent damage was observed on medium sprayed concentration fields. And highest percent damage was observed on high sprayed concentration fields as compared to control. So these results explicitly reveal that Chilo partellus in Pakistan does not pose any risk in sprayed maize fields. As a conclusion we can assert that there was no resistance developed in Chilo partellus against cypermethrin.