Purpureocillium is an essential natural bio-control agent and a source of mycopesticides for pest management of several insect orders all over the world. In this study, Purpureocillium lilacinum Egyptian isolate bioactive constituents and its insect host range were estimated.
The tested isolate was identified morphologically and molecularly by amplification of internal transcribed spacer (ITS) region using the polymerase chain reaction technique (PCR). The ITS sequence was compared with other Purpureocillium published isolates in genbank data base and our isolate showed that Purpureocillium lilacinum (MYS) (MT102250) isolate has 98% homology with most published isolates. The pathogenicity of the tested isolate P. lilacinum (MYS) was evaluated by using five concentrations of fungal spore suspensions and fungal filtrates against four pests, Bemisia tabaci, Tetranychus urticae, Thrips tabaci  and  Diuraphis noxia. The fungal filtrate had a higher toxic effect on all tested pests than the spore suspension. The greater fungal filtrate concentration resulted in higher mortality rates seven days post treatment, reached 100% for T. tabaci and T. urticae and 97% for B. tabaci and D. noxia, respectively. LC₅₀ values for spore suspension concentrations were 0.3x10² spore/ml for T. tabaci and T. urticae and 0.2x 10³ and 0.2x10² spore/ml for B. tabaci and D. noxia respectively and were 2% for T. tabaci and B. tabaci and 5 and 9% for D. noxia and T. urticae respectively with culture filtrate concentrations. GC-MS was used to estimate the bioactive components of P. lilacinus extracts, and about 31 secondary metabolites with different bioactivities were present, some of them identified as insecticides