Influence of weather parameters on population dynamics of thrips and mites on summer season cowpea in Eastern Plateau and Hill region of India

Abstract

Population dynamics of thrips, Megaleurothrips distalis (Karny) and mites, Tetranychus spp. were studied on summer season cowpea crop during 2013-2014 in Eastern Plateau and Hill region of India. Temperature, rainfall and host-plants were analyzed with respect to population fluctuation of pests. The population of thrips and mites were observed from low to high throughout the entire season and the incidence were more or less in the same pattern of the population fluctuation. Infestation of both thrips and mite initiated from 2nd week of March and continued up to the last week of June. The correlation analysis between thrips population and weather parameters indicated a strong significant positive correlation between the number of thrips and maximum temperature (p<0.01) and significant with the mean temperature (p<0.05). A significant negative correlation was observed between thrips population and rainfall, but a negative correlation with RH was found to be non-significant. Similarly, temperature showed positive and rainfall a negative correlation on mite population fluctuation. The linear regression model based on weather conditions as independent variable and thrips and mites population fluctuation as dependent variable, explained to 72 percent for thrips and 62 percent for mite population variability. Environmental factors played significant role in distribution and abundance of thrips and mites population.