Competitive Abilities of the Entomopathogenic Nematodes Steinernema feltiae and Heterorhabditis bacteriophora in the Same Host at Different Temperatures

The effectiveness of Turkish strains of the entomopathogenic nematodes Steinernema feltiae and Heterorhabditis bacteriophora on the last instar larvae of Tenebrio molitor were investigated. Mortality rates of T. molitor larvae caused by each nematode species alone (experiment I) were determined. Then, with the same method, the effectiveness of each species over theother in competition was examined (experiment II). Both experiments were conducted in sterilesand at 12, 18 and 25 ¡C for 5 days.While in experiment I the efficiency of the species was determined to be 52.5% for H. bacteriophora and 85% for S. feltiae at 12¡C, 93.5% and 95.6% at 18 ¡C for H. bacteriophora and S. feltiae, respectively, and 97.5% at 25 ¡C for both species, in experimentII these rates were 3% and 72% at 12 ¡C; 8% and 85% at 18 ¡C and 12.5% and 80% at 25 ¡C for H. bacteriophora and S. feltiae,respectively. The results indicated that S. feltiae was noticeably dominant over H. bacteriophora when both species were applied together at 3 different temperatures.