Vol. 7, Issue 12, Part D (2021)

Abstract
The results on dosage mortality response of various indigenous EPN isolates viz., Heterorhabditis spp. (PKV-1), Heterorhabditis spp. (CICR Brown), Steinernema bicornutum. (CICR-White) and Heterorhabditis spp. (PKV-Guava) against the all-instar larvae S. frugiperda (excluding 1st instar) revealed that in case of Heterorhabditis spp. (PKV1) LC50 for 2nd instar larvae of S. frugiperda was calculated 6.65, for 3rd instar 4.79, for 5th instar 5.39, for 5th instar 8.31 and for 6th instar it was calculated as 6.44. While in case of Heterorhabditis spp. (CICR- Brown) the lowest LC50 value 2.29 calculated for the 3rd instar larvae, then 2.72 for 5th instar larvae 4.127 for 2nd instar, 4.98 for 6th in star and highest LC50 calculated for 4th instar larvae. While in case of Isolate Heterorhabditis spp. (PKV-Guava) the lowest LC50 value calculated as 5.86 in 5th instar larvae, 6.76 in case of 4th instar, 7.31 in 3rd instar and 7.52 in 2nd instar and EPN isolate Steinernema bicornutum has recorded the lowest LC50 calculated 22.23 for 4th instar larvae, 23.14 for 2nd instar, 26. 4 for 5th instar, 28.08 for 3rd in star and 58.78 for 6th instar.