Population Dynamics of the Coriander Aphids in Hyper Arid Region of Rajasthan and their Correlation with Biotic and Abiotic Factors

Population dynamics of coriander aphid and their correlation with biotic and abiotic factors were studied at instructional farm of the department of Entomology, College of Agriculture, SKRAU Bikaner during Rabi, 2020-21 and 2021-22. The incidence of coriander aphid, H. coriandri (Das) commenced in the fourth week of January (4th SMW) and remained active throughout the crop season i.e. upto third week of March during both the years (2020-21 and 2021-22). The population of H. coriandri increased gradually and attained its peak in last week of February/first week of March (9th SMW) during both the years. After peak aphid population started declining and reached to low levels in the 11th SMW near maturity of the crop during both the years. Simultaneously the occurrence of predator, Coccinella septempunctata coincided with the population of aphids during both the years. Maximum and minimum temperatures had positive correlation with aphid population during both the years i.e. 2020-21, 2021-22. Morning and evening relative humidity showed negative correlation with aphid population. whereas, population of C. septempunctata was significant positively correlated with aphid population during both years.