Dynamics of insect-pests of paddy and its correlation with weather parameters
J Mary lisha, V Baskaran, S Vijay, M Vishnu
Rice is the stable food crop of more than 60 per cent of the world population. In this view, rice was sown in experimental plots. The experiment was laid out in Randomized block design with three replications. To monitor the pest net sweeping method was used. This investigation revealed that pest activity commenced from 35th Standard meteorological week (SMW) and continued to 41th SMW of the year 2018. Highest white ears (68 nos.) of Scirpophaga incertulas was found in 41th SMW, the maximum population (59 nos.) of Cnapholocrocis medinalis was recorded in the 37th SMW, the peak population of Nephotettix spp (95 nos.) was estimated in the 37th SMW, the highest number of Leptocorisa acuta (102 nos.) was recorded in the 41th SMV population. The results showed that the population of yellow stem borer, leaf folder, green leaf hopper and grasshoppers are positively correlated with maximum and minimum temperature, were as pollen feeders and Earhead bugs are showed negative correlation with maximum and minimum temperature respectively. The Relative Humidity (RH) is favourable for Earhead bug, Grasshopper and Pollen feeders are positive correlation except yellow stem borer, leaf folder and grasshopper. Sunshine hours favourable for all insects like Leaf folder, Green leaf hopper, Grasshoppers, Pollen feeders in rice. Since, it showed a positive correlation with sunshine hours except Yellow stem borer and Earhead bugs.