Siddique S, Perveen Z, Chaudhry MN
Journal of Medicinal Plants Research, 2013
The uncontrolled use of synthetic chemicals is a great hazard for the environment and consumers. Essential oils were introduced as less toxic agents against mammals and non-targeted insects. In the present study, essential oils from five plant species belonging to family Myrtaceae were extracted using hydro-distillation and their chemical composition was determined by gas chromatography mass spectroscopy. The essential oils were found to be mixtures of hydrocarbons, alcohols, aldehydes and esters. The oils were also assayed for their insecticidal properties against 25 days adult of Tribolium castaneum (red flour beetle). The results showed that the selected essential oils of Eugenia jambolana, Myrtus communis, Melaleuca alternifolia, Melaleuca genistifolia, Sygygium caryophyllatumand Callistemon citrinus had repellency, fumigant and contact toxicities against T. castaneum. The repellency was observed after 24 h. All oils showed repellency at all the applied concentrations. The 100% repellency was shown by M. communis at concentration of 0.000013 ml/ml while S. caryophyllatum, M. alternifolia and C. citrinus showed 100% repellency at 0.0003 ml/ml. In fumigation and contact toxicity bio-assay, the percentage mortality increased with increasing concentration. C. citrinus gave 100% mortality at 0.68ml/ml air at exposure period of 4 h while M. alternifolia, M. communis and E. jambolanashowed 100% mortalities at 0.909 ml/ml air at an exposure period of 4 h. T. castaneum was found highly susceptible to S. caryophyllatum with LC50 value of 0.034 ml/cm2 when exposed to oil for 1 day. While for M. alternifolia, M. communis and M. genistifolia the LC50values were 0.042, 0.060 and 0.533 ml/cm2 respectively at exposure period of 1 day. These investigations showed that the selected essential oils can be used as alternative grain-protectants for stored-products insects.
Siddique S, Perveen Z, Chaudhry MN. Repellency, fumigant and contact toxicities of essential oils of selected species from family Myrtaceae against Tribolium castaneum. J Med Plants Res. 2013;7(3):126-139.