Studies on pest complex of sesame and their natural enemies in North Karnataka, India
Rojeet Thangjam and AS Vastrad
Sesame is attacked by numerous pests which reduce its yield both in quality and quantity. To study the pest complex of sesame and their natural enemies, roving survey and fixed plot survey was conducted in North Karnataka and in Agricultural Entomology field, MARS, UAS, Dharwad during Kharif -2011 and summer-2012. Altogether 55 species of arthropods were found to be associated with sesame, out of which 30 species were identified as pest and 25 as natural enemies including 2 strains of entomopathogen. Among the different insect pests recorded, highest number of species was obtained in Heteroptera followed by Homoptera, Lepidoptera, Coleoptera and Thysanoptera. During Kharif 2011, 25 species were recorded however in summer 2012, only 22 species were recorded and their relative abundance was 53.19 and 46.81 per cent respectively. Out of 30 species recorded, Acherontia styx, Spilarctia oblique, Nezara viridula, Dolycoris indicus, Orosius albicinctus and Bemisia tabaci were the major pests but the occurrence of Oxycarenus hyalinipennis and unidentified mealybug was recorded for the first time which needs further investigation. Among the natural enemies recorded, 14 species were predators, 9 species were parasitoids and 2 strains of entomopathogen. The activity of the natural enemy was highest during Kharif 2011 than summer 2012 and their relative abundance was 58.33 and 41.67 per cent respectively.