Fumigant and Repellent Effects of Essential Oil Fractions of Mentha piperita against Tribolium castaneum (Coleoptera: Tenebrionidae)

Abstract

Tribolium castaneum<em> is one of the important stored-product pests in tropical countries. Fumigation with phosphine is the most commonly method to control </em>T. castaneum<em>. However, long-term application of phosphine will cause resistance. The aims of this research were to study the effects of fumigant and repellent of peppermint oil </em>Mentha piperita<em> fraction against </em>T. castaneum<em>, and to identify the compounds contained in the active fraction. This research was conducted in Entomology Laboratory Seameo Biotrop and <em>Forensic Laboratory of Indonesian Police Headquarters Jakarta</em>, from January to October 2016. <em>Peppermint oil</em></em> <em>was</em> <em>extracted by</em> <em>distillation from the leaves of M. piperita</em>.<em> Peppermint oil was fractionated by counter-current distribution method using three solvents: n-hexane, ethyl acetate, and methanol. Then, the three fractions were tested as fumigant and repellent against </em>T. castaneum<em>. The active fraction of essential oils were identified by GC-MS. The n-hexane fraction of peppermint (HFP) was the active fraction caused mortality on larvae and adults of </em>T. castaneum<em> at 72 hours after fumigation. The LC<sub>95</sub> values for the adults and larvae was 1.9 % and 9.43 % , respectively. Sublethal concentration of HFP showed inhibitory activity on larvae</em> <em>development. Percentage of pupae transformed from treated larvae was 48.67-74.91 % and percentage of adults emerged was 9.12-16.59 %. The repellent activity of HFP on adults of T. castaneum was 86.7 % at 72 hours after treatment. The dominant compounds of HFP was β-pinene, limonene, isopulegol, menthone, isomenthon, menthol, pulegone, and trans-carane. The HFP or its compounds was potential to be develoved as botanical insecticides.</em>