EVALUATION OF SIX INDIGENOUS ENTOMOPATHOGENIC NEMATODES AGAINST TERMITE, ANACANTHOTERMES OCHRACEUS (ISOPTERA: HODOTERMITIDAE) UNDER LABORATORY CONDITIONS

Subterranean termites, Anacanthotermes ochraceus, are a widely distributed and mainly recognized in Saudi Arabia as agricultural pests and economically serious insects causing damage to wood structures.Because termites have a cryptic feeding habit and have developed resistance to several insecticides, the effectiveness of most synthetic insecticides against them has been diminished.This study was designed in laboratory using sawdust and sand bioassay to confirm six native entomopathogenic nematode (EPN) isolates' effectiveness including Steinernema feltiae NEM-29, S. feltiae AHN, Heterorhabditis indica NEM-19, H. indica NEM-18, H. bacteriophora NEM-26 and H. bacteriophora AHN22 against workers of A. ochraceus.Results revealed that termite worker mortality was higher in the sawdust bioassay than in sand bioassay.At both tested assay methods, S. feltiae had a significantly greater mortality rate, followed by H. indica and H. bacteriophora.The maximum mortalities (100% and 79.0%) was recorded for S. feltiae AHN at 1000 IJs/termite with lower LC50 values of 7.3 and 73.8 IJs/termites at 16 d-post exposure in sawdust and sand assay, respectively.All tested EPN strains reproduced successfully and emerged from dead A. ochraceus workers in 8-14 days with higher reproduction rate (22,193 IJs/termite) for S. feltiae AHN in sawdust bioassay.Conclusively, it has been discovered that native EPNs can control termites more successfully, presumably due to they have the ability to spread further infections via infected dead individuals and can directly interact with termite pests in the soil.