Colonies of the red flour beetle,T. castaneum,were maintained in the
laboratory without exposure to any insecticide. They were reared in
plastic rearing containers (16 cm diameter×22 cm height) covered by a
fine mesh cloth for ventilation. Each contained a mixture of wheat flour,
wheat germ, and yeast extract (13:6:1 w/w/w). The cultures were
maintained in a growth chamber at 25±1 °C, 45-50% r.h., and 16:8 h
light:dark photoperiod. Only adults were used for the toxicity and
repellency tests