Comparative virulence of Steinernema glaseri steiner and Steinernema carpocapsae (Weiser) to the chafer Holotrichia consanguinea (Coleoptera: Scarabaeidae)

A laboratory test was made to assess the virulence of Steinernema glaseri (Strain NC-34) and S. carpocapsae (Strain DD-136) to the final instar grub of the chafer, Holotrichia consanguinea, using filter paper exposure method at 25°C, at dosage levels of 0, 5, 10, 20 and 40 infective juveniles (IJs) per grub. LC₅₀ values were 15.38 and 33.84 IJs for grub and LT,, values ranged from 152.0–85.0 -h and 223.8–119.1-h, both being dosage dependent, for S. glaseri and S. carpocapsae, respectively, thus establishing that the former was more virulent.