Fumigation Efficacy of Ethyl Formate against Tribolium Castaneum ( Herbst )

摘要

The lethal effects of ethyl formate (EF) on eggs, early larvae, late larvae, pupae and adults of T. castaneum were systematically studied in the laboratory under different dosages, treatment times and temperatures. The results indicate that treatment time and temperature significantly affect fumigation efficacy of EF on T. castaneum. There was a significantly higher fumigation activity of EF within 48h,and the fumigation efficacy at lower temperatures was better than that at higher temperatures. At 20,25 and 30℃ and 24h fumigation,the LC500 values of adults were 24.24,27.52 and 29.95 μL/L,respectively;whereas 48h of fumigation produced corresponding LC50 values of 22. 18,25.74 and 27.30 μL/L, respectively. EF was most effective against eggs and least effective against pupae. EF was most effective against T. castaneum in a simulated wheat storehouse and least effective in a simulated paddy rice storehouse. The corrected mortalities of T. castaneum in upper,middle and lower layers of simulated wheat and maize storehouses were 100% with a dose of 70 g/m3 after 24 h treatment at 30℃,whereas in a paddy storehouse T. castaneurn can survive at all layers. When the EF dose was 90　g/m3, the corrected mortality in the upper layer was 100%,in the middle layer 19.3% and in the lower layer it was zero.