Reproduction potential of entomopathogenic nematodes on armyworm (spodoptera litura)

Abstract

Biocontrol potential of entomopathogenic nematodes (Heterorhabditis bacteriophora and Steinernema glaseri) against different larval instars (2nd, 3rd, 4th and 5th) of armyworm (Spodoptera litura F.) at different exposure times were evaluated. Entomopathogenic nematodes were applied at 1000 IJs/ml and larvae maintained at 25°C. Mortality was recorded upto four days. Both species of entomopathogenic nematodes proved effective against all larval instars. Maximum mortality was observed in 2nd and 5th larval instar. After the fourth day 100% mortality was observed in all larval instar. Mortality was increased with an increase in exposure time. Nematodes were harvested using White Traps. Multiplication of entomopathogenic nematodes was also recorded in all larval instar. The maximum number of H. bacteriophora was harvested from 5th larval instar which was 25, 786 followed by 17, 500, 12, 642 and 9, 652 from 4th, 3rd and 2nd larval instar, respectively.