The effect of high temperature on the mortality of Lasioderma serricorne (F.)

The effects of high temperature (45 and 50 oC) on the mortality of heat tolerant stages (eggs and cocoons) of Lasioderma serricorne (F.) were assessed in the laboratory as alternatives to the use of chemical control methods for the disinfestation of machinery in tobacco manufacturing premises. Insects were rapidly heated to each test temperature, exposed for seven exposure periods then rapidly cooled to 30 oC, to allow calculation of the lethal times (LT) for 50 % (LT50) and 99 % (LT99) mortality. At 45 oC in tubes, LT50 and LT99 values were 14.3 and 52 h and 13.4 and 50.3 h for the eggs and cocoons respectively, with no survivors after 54 h exposure. In jars at 45 oC, the LT50 and LT99 values for cocoons were 17.5 h and 67.5 h respectively with survivors at 48 h. At 50 oC in plastic dishes, LT50 and LT99 values were 3.4 and 10 hours and 1.4 and 6.6 hours for eggs and cocoons respectively, with no survival of cocoons after 12 h exposure. In tubes at 50 oC, the LT50 was 3.4 h and LT90 8.6 h for eggs. Th