Chemical constituents and fumigant toxicity of essential oils against insect pests of stored Rice

The laboratory studies carried out to find the chemical constituents of essential oils from leaves of Murraya koenigii, Curcuma longa and peels of Citrus reticulata and their fumigant toxicity against Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum in stored rice. The GC-MS profile of Murraya koenigii oil showed α pinene 27.4% as major constituents followed by β pinene 13.4% and sabinene 10.3%, while essential oil of Citrus reticulata contained limonene 69.3% followed by linolool 7.8% and myrcen 5.3% a major compound, the essential oil of Curcuma longa contain camphene 25.5% followed by α pinene 18.5% and α humilene 11.7%. The fumigant toxicity of essential oil of M. koenigii, C. reticulata or C. longa at 0.2% concentration or its two component combination at 0.1% each or three component combination at 0.07% each were found highly effective as they completely suppressed the feeding and breeding thus, caused 100% inhibition of S. oryzae, R. dominica and T. castaneum.