Lc Biological Activity Of Tobacco Powder Borer And Its Sustained-release Formulations Of The Natural Product

Ephestia elutella(Hübner) is a primary pest in stored tobacco pests during tobacco storage.On the base of preliminary work in our laboratory,bioactivity of natural product LC against Ephestia elutella was further studied.β-CD was used to encapsulate essential oil of natural product LC and a formulation of 30%natural product LC capsule suspension(CS) has been successfully formulated on the base of screening of the biological activity.And a formulation of 10%natural product LC granule also has been successfully formulated.Some theoretical values and applications of the results are achieved.1.The results of bioassay show that natural product LC has good bioactivity against E.elutella.After the treatment of 24 h:the emendation death rate of adults and larvae of E.elutella were 96.59%and 93.07%and at the dose of 128μl/ml and 256μl/ml.After the treatment of 24 h,72 h and at the dose of 16mg/ml and 4mg/ml,the average repellent rates of natural product LC against larvae of E.elutella were more than 75%;After the treatment of 24 h and at the dose of 16mg/ml,the average contact activity of natural product LC against E.elutella larvas was 88.31%.After the treatment of 48 h and at the dose of 16mg/ml,the average toxic activity of natural product LC against E.elutella larvas was 92.82%.The growth inhibition rate of natural product LC to E.elutella larvas was 13.02%at the dose of 16μg/g.2.The results of the CS indicate that the optimal conditions were as follows:the active ingredient content of 30%,the rotating speed of 900r/min,the proportion of natural product LC:β-CD of 5:10,the capsule temperature of 50℃,the amount of water of 100ml.By screening agents of the type and quantity,surfactants were identified at the dose of 4%0204C and 4%OX-713,thickener at the dose of 1%of PVA,cryoprotectant at the dose of 5%of glycol.3.The parameters of the CS including the active ingredient content,the rate of capsule,density,suspension rate,dumping,dispersion and thermal storage stability were measured.The results show that the appearance was milk white viscous suspension,the active ingredients was above 30%,the capsule rate of active ingredients was above 85%,the density was about 1.008g/ml,the suspension rate was above 50%,the remnants of dumping and washing was less than 8%and 3%,the dispersion and thermal storage stability were better.4.The results of the granule indicate that the optimal conditions were as follows: the active ingredients was above 10%,the carrier of 70.2%,the sorbent of 16%,the binder of 2.5%,the dispersant of 0.5%,the others of 0.8%.The results also indicate that the optimal coation time of 45 min.5.Confirming the technical criterion of 10%natural product LC granule:the appearance was relaxed and flowed free granule,the active ingredients was above 10%,the pH range of 6.5-7.0,the granularity range of 3—9mm,the drop rate of 4.92 %,the decomposition was no more than 5%.6.The result of CS and granule against E.elutella in the actual warehouse of the simulation experiments indicate that it had better treatment actions.After 10 days the controlling effect had reached to 73.32%at the concentration of diluting 100 multiples of CS;and after 10 days the controlling effect had reached to 50.00%, which was above the controlling effect of DDV.