Seasonal abundance of major insect pests of potato (Solanum tuberosum) and their natural enemies in Karnataka, India

Abstract

It is essential to know the seasonal occurrences of various pests of potato along with their natural enemies so that timely management practices could be advised to farmers to avoid losses. Therefore, field studies on seasonal incidence of major insect pests of potato and their natural enemies were carried out at the All India Co-ordinated Research Project on Potato, Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, India during Kharif 2016 and 2017; and at Hangaraki, a village near Dharwad during Rabi 2016-17 and 2017-18. The observations on the seasonal abundance of potato insects, mites, and their natural enemies were recorded at weekly intervals starting from 20 days after the emergence of the plant till harvest. These observations were made under unprotected conditions. During Kharif season, the sucking pests were active from July second week and continued up to harvesting of the crop and the maximum pest population was observed during August second week to September first week. The peak activity of the shoot borer, Leucinodes orbonalis Guenee was noticed during the 35th Meteorological Standard Week (MSW) (i.e., August). The maximum population of defoliator, Spodoptera litura (Fab.) was noticed during 34th MSW. The higher populations of coccinellid beetles and spiders were recorded during 35th MSW while chrysopid activity was maximum during 36th MSW (September). During Rabi season, the sucking pests were active from October second week and attained peak during the second and third week of November. The maximum activity of aphids and leafhoppers was noticed during the 46th and 47th MSW (November), respectively. The highest incidence of thrips was recorded during the 48th MSW. The peak population of whiteflies and mites was recorded during the 46th and 45th MSW, respectively. The peak activity defoliator and shoot borer were noticed during the 45th and 46th MSW, respectively. The chrysopid activity was maximum during 46th and 47th MSW.