Optimization of in vitro solid culture of heterorhabditis bacteriophora HBH hybrid strain

Entomopathogenic nematodes (EPN) are widely used biocontrol agents. EPNs are living under soil and they need an insect host to continue their biology. EPNs kill their insect host and emerge into soil to seek new hosts. They have active host-seeking ability, they can be applied with standard sprayers, they have lethal effects over 250 insects and they are safe for non-target hosts and environment. EPNs have become popular in bio-pesticide market due to their positive features. However, one of their important disadvantage is the high price of commercial products. Thus, studies about EPNs mostly focused on improving mass production techniques and reduce production costs by optimization of production media and physical conditions. In Nematology Laboratory of Bursa Uludag University, Faculty of Agriculture, Department of Plant Protection, a hybrid strain was developed from different EPN isolates obtained from different climatic regions of Turkey and patented due to its superior bio-ecological characteristics. Heterorhabditis bacteriophora HBH hybrid strain is belong to our country and it is bio-ecologically adapted to Turkey. In this purpose, optimization of in vitro production and yield improvement of HBH hybrid strain was aimed. With yield improvement, reduction in production costs is also expected. In the present study, different production media with supplementary ingredient (soy lecithin, egg yolk), temperature (24, 28 and 32 °C) and media pH (5, 7 and 9) were selected as in vitro production parameters. Regarding the hermaphrodite egg numbers and total infective juvenile results obtained from different in vitro solid productions, best production combination was found as medium containing soy lecithin, 28 °C and pH 7. Moreover, media with pH 9 were showed statistically negative results compared to other combinations on all parameters. Consequently, optimum values for some important in vitro solid production parameters of HBH hybrid strain were determined