Sitophilus oryzae L and Callosobruchus chinenesis L and adults of Blattella germanica L, M. domestica and C. pipiens pallens(Coquillett) and Musca domestica ElNahal et al stated that the period of exposure appears to be more important than dosage in influencing the efficiency of the vapours of Acorus calamus essential oil to adults of five stored product insect species