A current study was established in laboratories of Biological Control Department, Shandaweel Research Station, Agricultural Research Center. Herbivore induced plant volatiles may be attractive to one or more specific natural enemies. Releasing of volatiles from certain pests and host injured plants has a role in host or prey location. Response of newly emerged and starved or fed adults (for three days) for each of Coccinella undecimpunctata (Coleoptera: Coccinellidae) and its parasitoid adults, Tetrastichus coccinellae Kurd. (Hymenoptera: Eulophidae) to volatile sources were studied. Olfactory orientation was emitted from a combination of host plant and host insect that volatiles from four sources (e.g. infested sorghum plants with aphids (corn leaf aphid (Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae)), crushed un-infested sorghum leaves and infested sorghum leaves plus the last larvae and newly pupated coccinellid). Results demonstrated the complexity of the use of different volatile info-chemicals generated by the different environmental stimuli. Reactions of the used C. undecimpunctata adults and its parasitoids were noticed and different strategies to exploit these signals were evolved.