author(s)
Madiha Mobeen Khan, Imran Akhtar, Syed Waqar Hussain Shah, Muhammad Shafiq and Manzoor Hussain

abstract
The study was conducted to evaluate plant oils Datura inoxia, Nigella sativa, Trachyspermum ammi and Amaranthus viridis for their effectivity on three strains of Tribolium castaneum. The T. castaneum was reared in laboratory to obtain F₁. The essential oils of plants were obtained by Hot Continuous Extraction method. The repellency tests were carried out by area preference method. Whereas, the toxicity was studied by using diet incorporation method. Later on the growth regulatory effects of plant essential oils were studied by regularly recording the data of survivors. All the plant appeared to have repellency against insects. Highest mortality was exhibited by D. inoxia (25.02%). Larval emergence was lower when treated with N. sativa (21.7%) and A. viridis (22.8%). Pupal formation was minimum at D. inoxia (2.622). Population build up was suppressed in all cases when compared with control. D. inoxia give maximum suppression (0.47% increase per insect). Based on the above results it can be concluded that D. inoxia appeared to be toxic in most of cases causing direct mortality. N. sativa was found effective in reducing larval emergence and pupal formations. However population build up data exhibited varied results on different plants.