studies on repellency of sirinol on tribolium castaneum (herbst) (col.: tenebrionidae) and oryzaephilus surinamensis (l.) (col.: cucujidae) with three exposure methods under laboratory conditions

in recent years a large number of pesticides used in the warehouses fumigation have been abandoned, and only methyl bromide and phostoxine are widely used for fumigation of foodstuffs and storage spaces. due to possibility of health impairment, environmental contamination and resistance enhancement of insects, the use of these two fumigants is under scrutiny and restriction. under such circumstances the need for to find out a safe, convenient, durable and economically sound control method is of out most important. there is widely held that the application of repellents could be a useful control measure in foodstuff storages. in this line, the repellency of sirinol (garlic emulsion) was assayed on tribolium castaneum (herbst) and oryzaephilus suinamensis (l.). to this end, larvae and adults of t. castaneum and o. surinamensis using three exposure methods viz, petri-dishes, olfactometer y- shape tube and porous cups that are the evaluation of ordinary methods of repellency, were exposed to 0, 0.5, 1, 5 and 10 percent concentration of sirinol. in petri-dishes technique using 10% concentration of sirinol, the maximum repellency rate occurred for larvae and adults of both species at 12 h, which were articulated 70.44% and 74.52 %, respectively. the sirinol’s repellency rate for adults of t. castaneum and o. surinamensis was 81.51%, and 74.5% at 72 and 48 h, in a similar order. the maximum repellency of sirinol using olfactometer y- shape tube was detected 71.11 and 66% for adults of t. castaneum and o. surinamensis at concentration of 10% and 24. 14 h. for porous cups technique, maximum repellency rate for adults of both test insects was observed for concentration of 10% and 12 h, and it was 46.15% for t. castaneum and 39.78% for o. surinamensis, respectively.