Lethal Effect of Phosphine on Different Stages of Liposcelis bostrychophila Badonnel

Lethal effects of phosphine (PH3) on egg, nymph and adult of L.bostrychophila were conducted in laboratory and lethal concentration was systematically determined in this research. In addition, L. bostrychophila was treated with PH3 intermittent fumigation and alternative treatment of controlled atmosphere (CA) and PH3. And then compare the control efficiency of different treatments on L. bostrychophila population. Results showed that PH3 fumigation had different lethal effects on different stages of L. bostrychophila. After 24, 72 and 120 h exposure, LC50 of egg were 0.137, 0.045, and 0.035 mg/L,respectively; after 24 h treatment, LC50 of nymph varied in the rage of 4.28~7.36 μg/L, and that of adults was 20.404 μg/L. Exposed to 25 μg/L PH3 for 24 h every 10 d, the population was completely controlled. And after alternative treatment with PH3 (12 μg/L) and CA (35% CO2, 1%O2, 64%N2), the resistance of population was delayed, and the occurrence of L. bostrychophila was completely controlled after the alternative treatment for 3~5 times.