Influence of environmental factors on the population dynamics of chilli thrips, Scirtothrips dorsalis (Hood) and aphid, Aphis gossypii (glover)

Abstract

Insect pests continue to pose a major threat for achieving higher production of chilli crop. The experiment was conducted to study population dynamics of chilli thrips and aphids at Varanasi on 100 m2 unsprayed field during 2016-17. The chilli thrips and aphid population were counted from ten randomly selected chilli plants and the abiotic factors like temperature, relative Humidity (RH), rainfall were also recorded. Result of the study revealed that chilli thrips population first appeared during the third week of September and reached its peak during the third week of October. However, the incidence of the aphid population commenced from the fourth week of September and attained peak population levels during the fourth week of October. Further the correlation analysis of abiotic factors with chilli thrips population showed that the positive correlation with maximum temperature whereas, a negative correlation with relative humidity during morning, relative humidity during evening, minimum temperature and rainfall were also observed. While the aphid population showed positive correlation with maximum temperature. However, negative correlations were observed with relative humidity during morning, relative humidity during evening, rainfall and minimum temperature. These results of present study help in the development of the forecasting model and timely preparedness to manage pest problems and prevent crop losses. © 2019, Editorial board of Journal of Experimental Biology and Agricultural Sciences. All rights reserved.