Investigation on the population dynamics of sugarcane plassey borer, Chilo tumidicostalis Hmpsn (Lepidoptera: Pyralidae) was carried out in laboratory and fields during 2014-15 and 2015-16. The cane damaged by the insect started in case of primary infestation from first fortnight of April 2014 with a peak () in the first fortnight of July. In the case of secondary infestation, per cent incidence of the cane was observed lately in the second fortnight of June with a highest peak () in the first half of November. | Population dynamics of sugarcane plassey borer chilo tumidicostalis Hmpson (Lepidoptera: Pyralidae)