Entomopathogenic nematodes (EPNs) of the genera Heterorhabditis and Steinernema are available in the market for use as pest control agents. They are symbiotically associated with bacteria of the genera Photorhabdus and Xenorhabdus, respectively. Mainly, media development of EPNs as biological control agents is directed towards cost reduction, and it is possible for a variety of protein sources to be metabolised by the bacteria for optimal conditions for nematode reproduction. The aim of this research is to examine the LC50 with leaf disc assays at concentrations of 0.01, 0.10, 1, 10, 100 and 1000 ppm using TUREK® (Bt var aizawai), BITE® (Bt var aizawai) and THURICIDE® (Bt var kurstaki) on larvae of P. xylostella (n=180). The results from the field trial clearly indicated that the biocontrol agent B. thuringiensis (Bt) is superior to the chemical insecticide. B. thuringiensis is accepted as safe, readily mass produced, highly susceptible and easily formulated and applied as biological control agents for sustainable agriculture. Recent scientific progress has been helpful in providing better understanding of the biological and technical parameters that influence the process, thus enabling transfer of knowledge and application to industry. As a consequence, costs for nematode-based products can be significantly reduced.