The effect of fumigation on the phosphine-susceptible and -resistant strains in the T. castaneum was evaluated using phosphine, ethyl formate, and combination with phosphine and ethyl formate (phosphine+ethyl formate). The Lethal Concentration Time (LCT)50 analysis of susceptible strains, late larva showed that phosphine (0.13 mg·h / L), ethyl formate (80.91 mg·h / L), and phosphine + ethyl formate (19.36 mg·h / L). The LCT50 of adult was 0.05 mg·h / L, 68.58 mg·h / L and 17.84 mg·h / L when treated with phosphine, ethyl formate, and phosphine + ethyl formate. The LCT50 of resistant strains, late larva was found to 33.32 mg·h / L of phosphine, 113.46 mg·h / L of ethyl formate and 129.85 mg·h / L of phosphine + ethyl formate, and the LCT50 of adult was 55.71 mg·h / L of phosphine, 85.39 mg·h / L, phosphine + ethyl formate 85.83 mg·h / L. The treatment of three fumigants (phosphine, ehtyl formate, and phosphine+ethyl formate) showed the possibility of controlling against T. castaneum of phosphine-susceptible and –resistant strains.
We divided the sample into four groups by temperature regimes and comparing the Lethal effect after exposure to high room temperatures for 50~58 days. After inoculating Cnidium officinale Makino with Tribolium castaneum Herbst, the storage insects of medicinal herbs, was 20 respectively. The results of treating cut Cninium officinale Makino are listed below. Survival rate of group A by exposure of 5 times at 35~36.5℃ is less than 7.5%. Survival rate of group C by exposure of 5 times at 35.5~39.5℃ and group D by exposure of 23day at 37~44℃ is less than 2.5%. Especially in the case of group D, we found that complete eradication of the insect is difficult despite exposure high temperature for a long time. Also most of the grinded Cninium officinale Makino has the same patten but group B by relatively treated low temperature has a significant difference in mortality. Insect mortality in cut Cninium officinale Makino by exposure at 35℃ and 39.5℃ is 7.5% and the insect mortality in grinded Cninium officinale Makino by exposure at 39. 5℃ is only 75%. The reason is estimated that heat conduction of grinded Cninium officinale Makino is slow and it was less shocked by heat because The final core temperature of medicinal herbs is relatively low about 0.5~2℃. This means that storage insect(Tribolium castaneum Herbst) can be suppressed at mid-high temperature if it is to be treated more than 50 days without problem of quality deterioration of medicinal herbs that can be caused by high temperature.