Various application methods for the entomopathogenic nematode Heterorhabditis bacteriophora were evaluated under laboratory and field conditions. Four different methods of applying the infective juveniles (IJs) of the nematode to soil were assessed including insect cadavers (referred to as nematode-infected cadavers), subsurface injection, praying and drip irrigation. | Turkish Journal of Agriculture and Forestry Research Article Turk J Agric For (2015) 39: 277-285 © TÜBİTAK doi: Efficacy of the entomopathogenic nematode Heterorhabditis bacteriophora using different application methods in the presence or absence of a natural enemy 1,4 2, 3 4 3 Ramalingam Karthik RAJA , Canan HAZIR *, Arife GÜMÜŞ , Cem ASAN , Mehmet KARAGÖZ , Selçuk HAZIR 1 Department of Biotechnology, Periyar University, Salem, Tamil Nadu, India 2 Aydın Vocational School of Health Services, Adnan Menderes University, Aydın, Turkey 3 Department of Plant Protection, Faculty of Agriculture, Adnan Menderes University, Aydın, Turkey 4 Department of Biology, Faculty of Arts and Science, Adnan Menderes University, Aydın, Turkey Received: Accepted: Published Online: 4 Printed: Abstract: Various application methods for the entomopathogenic nematode Heterorhabditis bacteriophora were evaluated under laboratory and field conditions. Four different methods of applying the infective juveniles (IJs) of the nematode to soil were assessed including (1) insect cadavers (referred to as nematode-infected cadavers), (2) subsurface injection, (3) spraying, and (4) drip irrigation. In the laboratory experiment, except for the control with no nematodes, all treatments showed more than 95% insect mortality of the bait insect (Galleria mellonella) with no significant differences among treatments. The same experimental setup was conducted with the introduction of mites, Sancassania polyphyllae (Acari: Acaridae), which are natural enemies of entomopathogenic nematodes. The treatment groups with mites and the control group without mites showed more than 87% insect mortality and no significant differences were observed. The nematode-infected cadaver application method was further evaluated by using cadavers of different ages containing H. bacteriophora IJs in the presence of