Efficiency of selected pesticides and integrated pest management approaches for control of Chilo suppressalis (Walker) (Lep.: Crambidae) in double cropping rice systems

In this study, the population density and survival of overwintering larvae of Chilo suppressalis (Walker) (Lep: Crambidae) was compared between single- and double cropped rice fields in north of Iran (Amol) during winter months (November-March) of 2016-2017. According to the results, a significantly higher frequency of overwintering larvae was observed in double cropped fields in both growing seasons and during all overwintering months. Additionally, larval mortality in double cropped fields was significantly lower than those in single cropped fields. The efficiency of three pesticides, diazinon (with two formulations G 10% and EC 60%), hexaflumuron (EC 10%) and fipronil (G 0.2%) as well as an integrated pest management approach (IPM) using mechanical, physical, and biological methods for control of Ch. suppressalis in double cropping fields of Amol was investigated during growing seasons of 2016 and 2017. According to fields experiments, a single application of hexaflumuron or diazinon EC at a concentration of 1.5 L/ha against the first instar larvae resulted in the most decrease in dead heart and white head damage and the highest crop yield in both growing seasons. The effect of IPM approaches on damage and crop yield was also considerable among treatments. Results of this study indicate that hexaflumuron, as an insect growth regulator (IGR) can be efficiently integrated in management programs of Ch. suppressalis. Besides environmental advantages, the integration of insecticides with novel modes of action in rotation with convenient pesticides can decrease the rate of resistance development by the pest in double cropping systems.