Studies on the population dynamics of thrips Scirtothrips dorsalis Distant and aphid Aphis craccivora Koch on groundnut Arachis hypogaea L and their safer management

Abstract

The present investigation entitled Studies on the population dynamics of thrips, Scirtothrips dorsalis Distant and aphid, Aphis craccivora Koch. on groundnut, Arachis hypogaea L. and their safer management was carried out during two consecutive years i.e. 2018 and 2019 at NDF, Kalyanpur of CSAUAT, Kanpur (U.P.). The initial infestation of Scirtothrips dorsalis during Kharif, 2018 was started from 31st SW and continued up to 46th SW (last week of July to 2nd week of November) and results also revealed that the pest population increased from 37th SW (1.6 thrips/5 plants) to 41st SW (3.3 thrips/5 plants) and declined, thereafter up to 46th SW (0.3 thrips/5 plants). The maximum population of 3.3 thrips/5 plants was recorded during 41st SW in 2018 and 4.6 thrips/5 plants was recorded at 38th SW during 2019 meanwhile at that time maximum temperature (i.e. 34 ºC and 29.3 ºC, respectively) and minimum temperature (i.e. 19.8 ºC and 24.1 ºC, respectively) recorded for both the years. The average relative humidity was recorded in terms of 77 and 89 per cent, respectively, for both the years while total rainfall was observed nil in 2018 and 20.4 mm. in 2019. The initial infestation of aphid during Kharif, 2018 and 2019 was 0.6 and 1.0 mean number of aphid population at 30th SW and 31st SW, respectively. The aphid population Major Advisor Ph.D. Scholar Dr. R. K. Dwivedi Anuj Shakya Asstt. Professor Deptt. of Entomology Deptt. of Entomology Id. No. CA-10862/18 increased gradually and reached its peak on 41st SW i.e. 9.6 and at 43rd SW i.e. 9.3 mean numbers of aphid for both the years, respectively. The maximum and minimum temperature prevailed during the study period was 34.0 ºC and 30.5 ºC and 19.8 ºC and 16.7 ºC, respectively, and the average relative humidity was recorded in terms of 77 and 88 per cent, respectively, while total rainfall was observed nil for both the years.The correlation matrix indicated a significant positive correlation with maximum temperature (r = 0.501) with thrips and (r =0.535) with aphid infestat