author(s)
Matangi Mishra and U Mukherjee

abstract
A study was conducted at Tirhut College of Agriculture, Dholi, Muzaffarpur, Bihar during the rabi season in the years 2017-18 and 2018-19. The natural enemies started arriving in the sixth standard week each year. Initially the population was low but as the time advanced, population of Coccinella septempunctata and Syrphid fly started increasing. The population of Coccinella septempunctata was always found more than the Syrphid fly in both the experimental years. Rainfall was having not any significant role in their population outburst while the correlation of Syrphid fly was found positive with maximum temperature and minimum temperature (0.309 and 0.291 respectively) during the first year i.e. 2017-18. However, it was found negatively correlated (-0.280) with relative humidity at 1400 hr and positive and non -significant correlation (0.468) was between Syrphid fly and relative humidity at 0700 hr. in the first year i.e. 2017-18. In the second experimental year (i.e. 2018-19) both the maximum temperature as well as minimum temperature was having a negative correlation with Syrphid fly (-0.104 and -0.132) respectively. Meanwhile, relative humidity at 0700n hr was 0.332 and 0.497 at 1400 hr. The rainfall and the number of rainy days were having negative correlation.