Evaluación de la Virulencia de Steinernema riobrave y Rhabditis blumi contra Larvas del Tercer Instar de Spodoptera frugiperda¹

The virulence of the nematode Steinernema riobrave (Poinar and Raulston, 1994) and the native nematode Rhabditis blumi (Sudhaus, 1974), was evaluated against the fall armyworm Spodoptera frugiperda (J.E Smith). Both nematodes were used to inoculate third instar larvae of fall armyworm at 100, 250, and 500 infective juveniles (IJ) concentrations per larvae, to determine mortality every 24 hours for 7 days. The nematode S. riobrave produced 90% mortality at 500 IJ after 96 to 168 h post inoculation (p < 0.05), whereas R. blumi caused no mortality to larvae when inoculated at the same concentrations and evaluation times. Steinernema riobrave showed high virulence to the fall armyworm; therefore, this species was considered as a suitable pathogen to be used in efficacy tests in the field to control S. frugiperda.