repellent activity and fumigant toxicity of 18 essential oil on indian meal moth, plodia interpunctella

indian meal moth, plodia interpunctella hubner is one of the most important stored-product insects that are controlled by fumigants. however, the use of plant essential oils and their constituents may have the advantage over conventional fumigants in terms of low mammalian toxicity and can be used as alternatives to conventional fumigants. therefore, in this research, repellent activity of 18 plant essential oils was investigated on adults and last instar larvae of indian meal moth. also, fumigant toxicity of the essential oils was studied on first instar larvae. repellency of the essential oils on adults showed that anethum graveolens and rosmarinus officinalis were 100% activity. hyossopus officinalis and petroselinum sativum had the lowest (14.8%) repellency. the repellency on larvae was less than adults, which may be due to less movement ability of larvae. consistent with adult repellency, both of the r. officinalis and a. graveolens had high repellency on larvae. the results fumigant toxicity of the oils showed that all plants had lc50 values less than 26 µl/l air. indicating the strong fumigant toxicity caused on first instar larvae. a. graveolens was less toxic (lc50= 25.48 µl/l air); while cinnamomum zeylanicum, carum carvi, achillea millefolium and melissa officinalis were the most toxic with lc50 values of 2.12, 5.06, 5.20 and 5.57 µl/l air, respectively. consequently, most of these plant essential oils such as r. officinalis and a. graveolens, in terms of repellency, may have high potential for using in control program of indian meal moth in storage.