Abstract
Food grains were severely damaged by stored goods insects. The red flour beetle Tribolium castaneum, the cigarette beetle Lasioderma serricorne and the rice weevil Sitophilus orysae are some of the most destructive pests which attack raw cereals throughout the world. In stored grain mill, fumigation with synthetic fumigants was the most economical tool for managing stored pests. Nevertheless, the application of chemical pesticides caused adverse effects on humans and environment. Chloroform, acetone, methanol and water extracts and essential oil of Haplophyllum tuberculatum aerial parts were tested for their fumigant and repellent effect against adults of the three stored products pests (T. castaneum, L. serricorne and S. oryzae). GC/MS analysis of the essential oil resulted in determination of 19 compounds. The major constituents were β-phellandrene (16.17%), trans-p-menth-2-ene-1-ol, (13.22%) and cis-p-menth-2-ene-1-ol (8.29%). Thus, it seemed that the essential oil had the highest fumigant activity against L. serricorne after 12 h of exposure compared to the two other insects with a LC50 equal to 38.59 µ.l-1 air. The best repellency was observed for the chloroform and methanol extracts against T. castaneum. The respective repellent doses RD50 values were = 0.03 and 0.04 mg.ml-1 after 24 h of exposure. However, after 24 h of exposure acetone extract seems to be more repellent with respective repellent dose values of = 0.14 mg.ml-1 (RD50) against L. serricorne. H. tuberculatum essential oil and extract proved to be effective in control pest infestations in grains and dry food products.