author(s)
Munna Kumar Nishad, Mukesh Kumar, Deepak Ranjan Kishor and Shriti Moses

abstract
This experiment was carried out in kharif 2017 at experimental Pusa farm of Dr. Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar which is situated on the south and west bank of the river Budhi Gandak at an altitude of 52.92 m above mean sea level and lies at 25⁰98‟ North latitude and 85⁰64‟ East longitude. The pest infested the crop after four weeks of transplant, that is the stage of initiation of flowers and population of L. orbonalis was observed in the 38^th standard week i.e. from 5^th week after transplanting of experiment and it was continuously increased up to 43^rd standard week i.e. 10^th week after transplanting (19.24%), after that the population stabilized up to 48^th standard week and their after showed decreasing trend. It could be further inferred that the pest population in the beginning was low (2.73%), which gradually increased and reached at its peak (19.36%) in 47^th standard week. The maximum number of per cent infestation of brinjal shoot and fruit borer (19.36%) was recorded during 47^th standard week. On other hand minimum population of brinjal shoot and fruit borer (2.73%) was recorded during 38^th standard week that was initial infestation.