Study of Paddy Stem Borers Population Dynamics and Influencing Environmental Factors through Light Trap

Abstract

Rice crop is affected by many insect pests like White Stem Borer, Yellow Stem Borer and Pink Stem Borer. Rice stem borers are main pests affecting rice crop from nursery to physiological maturity including them in key pests. These studies had been carried out to discover the encouraging and antagonistic boundaries of weather parameters for the rice stem borers. As per result of studies, the population was recorded higher from mid-March to 1st week of May and then it escalated again from 2nd week of August to a maximum in September in case of Yellow Stem Borer (Scirpophaga incertulus) and White Stem Borer (Scirpophaga innotata) of rice during the both years 2017-2018; while in case of Pink Stem Borer population recorded from mid-September to the last week of April in 2017 and lasted till 4th week of May 2018. On evaluating the weather conditions specially temperature and relative humidity, it was detected that insect trap catches noted inside a certain range of temperature that varies from 18-35°C in case of White Stem Borer and 17-34°C for Yellow stem borer of rice. Extreme catches were documented in April and September inside a temperature range of 26-32°C considering it ideal series of temperature for insect light trap catches and activity of yellow and white stem borer. However, in case of pink stem borer above 32°C no catch was observed.