Population dynamics of major insect pests on soybean farmscaped with marigold

The major insect pests viz., whitefly, jassids, foliage-feeding weevils, leaf folder, semiloopers and the tobacco caterpillar were recorded for two successive crop seasons (kharif, 2015 & 2016) under farmscaping with and without marigold. The mean atmospheric temperature had significant positive correlation with major insect pests of soybean in kharif 2015, but in kharif 2016 the mean atmospheric temperature showed a significant positive correlation only with the population of weevils (r = 0.61) and other lepidopterans (r = 0.61); whereas, a significant negative correlation was exhibited for jassids and semiloopers. The total rainfall evinced a significant negative correlation with the whitefly and jassid population of soybean during 2015; whereas in the crop season 2016, the mean relative humidity showed a significant negative correlation with weevils and other lepidopterans. The population of weevils and other lepidopterans showed a significant negative correlation with total rainfall. The mean relative humidity and rainfall exhibited a significant positive correlation with semilooper population (respective correlation coefficient values being 0.88 and 0.59) during kharif, 2016. Among the insect pests of soybean, jassids had the maximum seasonal mean population, mean density and relative density during both years as compared to other insect pests both under marigold farmscaping and without marigold farmscaping in soybean. The Shannon-Weiner Diversity Index values did not vary significantly when soybean was cultivated under farmscaping with marigold and without farmscaping.