International Journal of Entomology Research

Authors
Istiak Mahfuz, Rojina Khatun, Nusrat Jahan, Rumpa Akhter, Shah HA Mahdi

Abstract
The current investigation was intended to control T. castaneum and S. oryzae using an alternative method rather than to use the traditional one. For this purpose, different doses (251.49, 125.75, 62.87, 31.44 and 15.72 µg/cm2) of lavender and rosemary essential oils (EOs) was tested against T. castaneum and S. oryzae, to determine the repellent effect of these oils through repellency bioassay and the measurement of percent repulsion on selected doses at hourly interval up to 5 hours. Percent repellency of lavender EO showed highest repulsion of T. castaneum in lower doses i.e., 31.44 and 15.72 µg/cm2, and in S. oryzae very high repellent effect was found in 62.87 µg/cm2. ANOVA data showed that the doses of lavender oil have significant (P=0.0017) effect on S. oryzae, although, in T. castaneum the effect of the doses is not significant (P=0.5639). The exposure time of S. oryzae in selected doses of lavender EO exhibited highly significant (P=0.0006) effect on repulsion, while in T. castaneum it was moderately significant (P=0.0162). Both in T. castaneum and S. oryzae, the interaction between exposure time and doses found to be not-significant. The percentage repellency of rosemary EO against T. castaneum was found to be highest in the doses of 62.87 and 31.44 µg/cm2, whereas, in S. oryzae highest repulsion was found in 251.49 µg/cm2. The ANOVA of repellency data showed a significant effect of time (P=0.0026), doses (P=0.0129), and interaction between time and doses (P=0.0112) against T. castaneum adults. In case of S. oryzae, exposure time, doses, and interaction were found to be not significant when tested with rosemary EO. With more research on the dose parameter, exposure time and active ingredient of the selected EOs, the current findings may lead to a very effective way and a potent source to control T. castaneum and S. Oryzae in storage which in turn can minimize the uncontrolled use of synthetic and/or chemical pesticides.