Characterization of biocontrol traits of heterorhabditid entomopathogenic nematode isolates from South Benin targeting the termite pest Macrotermes bellicosus

摘要

Twenty-nine Beninese isolates of Heterorhabditis sonorensis and one local isolate of H. indica were screened in bioassays for their pathogenicity against Macrotermes bellicosus and for their tolerance to heat (40 A degrees C), desiccation (25 % glycerine) and hypoxic conditions. The bioassays showed significant differences among isolates for all tested traits. Most of the isolates (73 %) killed more than 80 % of the insects. The greatest survival of infective juveniles to heat (8 h), desiccation (8 h), and hypoxia (72 h) was observed with the H. sonorensis isolates Kassehlo (72.8 %), Setto1 (72.5 %), and Kissamey (81.5 %, respectively). Hierarchical cluster analysis identified six clusters. One of the clusters grouped three isolates of H. sonorensis (Zoundomey, Akohoun and Kassehlo) that scored well for all traits. These latter isolates were similarly effective by suppressing within five days a population of M. bellicosus naturally imprisoned in 1,000 cm(3) containers and inoculated with a single two-weeks-old EPN-infected Galleria larva.