Population dynamics of planthoppers in rice ecosystem of Varanasi region, India

The abundance of brown planthopper was noticed in the field from 33^rd to 43^rd SMW and 32^nd to 46^th SMW and its peak was recorded in 41^st SMW (13.15 BPH/10 hills) and 42^nd SMW (33.51 BPH/10 hills) during kharif 2016 and 2017, respectively. The relationship between the population of brown planthopper and weather parameters showed a significant positive correlation with maximum (r = 0.514^*), minimum (r = 0.541^*) and average (r = 0.526^*) temperature and morning relative humidity (r = 0.578^*) during 2016. Whereas it was showed significant positive correlation with morning (r = 0.559^*), evening (r = 0.613^*) and average (r = 0.530^*) relative humidity, respectively during 2017. The abundance of white backed planthopper was noticed in the field from 33^rd to 42^nd SMW and 34^th to 46^th SMW and its peak was recorded in 41^st (10.60 WBPH/10 hills) SMW and 43^rd (17.30 WBPH/10 hills) SMW during 2016 and 2017. The relationship between the population of white backed planthopper and weather parameters showed a significant positive correlation with morning (r = 0.464^*), evening (r = 0.473^*) and average (r = 0.530^*) relative humidity during both the year of study, respectively.