Insecticidal Active And Action Ways Of Mythimna Separate W. On Datura. Tatula L．

Datura. tatula L., is a herbaceous plant of Solanaceae, Datura. In the experiment, the insecticidal activity of Datura. tatula L. extractive and the mode of action on Mythimna separate (Walker.) were studied, the main results are listed as follows:5 solvent with different polarities were used to extract the different parts of Datura. tatula L., among the many crude extracts, petroleum ether of seeds was found with highest output capacity, whereas stem and leaf in full flowering stage was found the lowest. Methanols with 6 moisture contents were used to extract stem and leaf in full flowering stage, the highest output capacity was found in 95% methanol, and the lowest was found in absolute methanol.Among the many crude extracts of Datura. tatula L. seeds, the strongest contact toxicity was found in petroleum ether, the corrected mortality of the 5 times diluted liquid reached 65.88%; strong contact toxicity of the extract was also found on Aphis gossypii (Glover.), Myzus persicae (Sulzer.) and Tetranychus urticae (Boiduval.), the corrected mortalities of which were found at 94.18%, 60.99% and 60%, respectively.During full flowering stage of Datura. tatula L., among the many crude extracts derived from stem and leaf with different solvents, the strongest contact toxicity on Mythimna separate (Walker) was found in methanol, the corrected mortality of which was at 17.93%; also, stronger antifeedant effect of the extract was found on Pieris rapae (Linnaeus.), the antifeedant rate of which was at 47.30%. The strongest contact toxicity of Datura. tatula L. on Mythimna separate (Walker.) was found in methanol crude extract, the corrected mortality of which was found at 20.83%, and stronger contact toxicity and antifeedant effect of the extract was found on 4th instar larvae of Pieris rapae (Linnaeus.), the corrected mortality of which was found at 100 % and 59.56%, respectively.Among the modes of function of the crude extracts obtained from different parts of Datura. tatula L. and extracted with different solvents, stomach poison was found in crude extracts obtained from methanol and seed petroleum ether on Mythimna separate (Walker.), the corrected mortality of which was at 28.75% and 21.43%, respectively; the crude extracts obtained from flower and the stem and leaf in full flowering stage could inhibit growth, the inhibition rate was at 59.67% and 45.89%, respectively; stem and leaf crude extract obtained from full flowering stage with methanol was found with strong anesthetic effect on Mythimna separate (Walker.), the anesthesia rate reached 80%, the regression equation was Y=3.3139+3.2543X, the revival time was RT50=3.3. No antifeeding, pupa killing, fumigation and systmic effect was found on methanol crude effect obtained from stem, leaf and flower in full flowering stage.