Observations on the life cycle and pathogenicity of Heterorhabditis amazonensis (Rhabditida: Heterorhabditidae)

Abstract

This paper deals with the life cycle and the pathogenicity of Heterorhabditis amazonensis ‘RSC5’ to Galleria mellonella, as studied under laboratory conditions. For the evaluation of the pathogenicity, insect larvae (ten per treatment) were incubated at 24 ± 1 °C for three to 16 days after nematode inoculation [20 infective juveniles (IJ) per larva]. The mortality rate of the larvae determined was 90 %. The same basic procedures were adopted in the study of the life cycle, but in this case two different nematode inoculum concentrations (5 or 400 IJ / larva) were used. Heterorhabditis amazonensis underwent either a short (216 h) or a long (384 h) biological cycle, producing two or three generations, respectively, depending on the amount of IJs inoculated into G. mellonella, with the larger inoculum inducing the shorter life cycle.