Study on the effect of combining modified atmosphere with nitrogen and deoxidizer on the survival of Tribolium castaneum

To clarify the control effects of different nitrogen volume fractions combined with deoxidizer treatment on different life stages of important stored grain pest, T. castaneum, the survival of eggs, larvae, pupae and adults of T. castaneum under nitrogen volume fractions of 78% (control group), 92%, 96% and 98%, with the addition of 0, 0.012, 0.024, and 0.048 g/L of 20-deoxidizers for 2, 4, 6 and 8 days, respectively. The results indicated that nitrogen volume fraction, deoxidizer dosage, and exposure time significantly affected the mortality rate of T. truncatum. Under the same dosage of deoxidizer treatment, the mortality rate of different life stages of T. castaneum increased with increasing nitrogen volume fraction and exposure time. Under the same nitrogen volume fraction condition, the mortality rate of various life stages of the T. castaneum increased with increasing exposure time. At the same exposure time, the mortality rate of different life stages of T. castaneum increased with increasing nitrogen volume fraction. However, the insecticidal effect of combined treatment with deoxidizer and nitrogen was higher than that of nitrogen controlled atmosphere alone. Under nitrogen volume fraction of 92%, 96%, and 98%, the lethal time of different life stages of T. castaneum was the shortest when the deoxidizer dosage was 0.012 g/L. Tribolium castaneum eggs were completely killed under nitrogen volume fraction of 92% after exposure for 8 days. After 4 days of exposure under nitrogen volume fraction of 96%, the mortality rate of larvae also reached 100%. The pupae were unable to emerge after 6 days of exposure at a nitrogen volume fraction of 98%. Adults could be completely killed after exposure at 98% nitrogen volume fraction for 8 days.