In this context, many plant-derived secondary metabolites have
been evaluated for their toxic properties in different stored grain
pests, especially in the form of essential oils (EOs) (Rajendran and
Sriranjini, 2008). EOs are mostly composed of complex volatile mixtures
of monoterpenes, biogenetically related phenols, and sesquiterpenes;
and in general, those are obtained through steam distillation of vegetative
structures of many plant species (Isman et al., 2007).