Insect population has changed both spatially and temporally over the period of time in a crop like rice. In the present study, data from the year 1965 to 2017 shows considerable increase of insect pests to 21 numbers. Their spread to large rice areas has been worked out which is a matter of concern, particularly Brown Planthopper (BPH), which has invaded all rice growing areas of the country. Present article focuses on more frequent occurrence of pests in different years related to the extent of damage incurred, which will be the principal concern of applied entomologists and farmers. Insects are classified as pests based not solely on numbers but on socioeconomic impact and on biological tolerance of the host to pest attack. In the present study, emphasis is placed upon host plant resistance to pests, proper monitoring and developing location-specific IPM packages for management of rice insect pests based on their initial populations and the processes by which they change to endemic form.