The primary and secondary forms of Photorhabdus luminescens a symbiotic bacterium of an entomopathogenic nematode Heterorhabditis indica (RCR) was evaluated against Tetranychus macfarlanei a serious non insect pest on cotton at the College of Agriculture, UAS, Raichur. The study revealed that the cells and cells free supernatant (CFS) of both the forms were lethal to T. macfarlanei. The primary and secondary form CFS (1010 cells/ml) recorded the mortality of 100 and 92.50 per cent, respectively compared to primary and secondary form cells which have recorded 76.25 and 81.25 per cent mortality, respectively. The concentration mortality response studies indicated that T. macfarlanei was more susceptible to CFS of primary form recording LC50 of 1.21 cells/ml compared to cells alone of primary form which recorded LC50 of 2.58× 106 cells/ml. Whereas, secondary form Cells and CFS has LC50 of 6.94× 106cells/ml and 1.5 cells/ml, respectively. These results indicate the potential of P. luminescens and its possible usage in management of T. macfarlanei.