Studies On Bioactivity Of Natural Product LC-1 To Diamondback Moth And Its Mechanism

Diamondback moth (Plutella xylostella L.) is an important insect on cruciferous vegetable, since it had produced resistance to most of used pesticides, e.g., trichlorphon and chlorpyrifos, it is difficult to control. Following the development of society and living level with people, the demand of vegetable innocuity is more and more bigger. Insecticides coming from botanical source have the characteristic of low poison, high-effect, low residue, it become the hot field of study and research around the world.Studies are based on results of Deng Kuan ping research, which is the natural product LC-1 bioassays to Pieris rape L. and the field trial. Take Diamondback moth as aim insect, and Mensurate the bioassays of kinds of action manner to Diamondback moth. By studying the impact of the nature product LC-1 oil to the active change of acetylcholine esterase and carboxyl esterase in the insect body inner and the extracorporeal insect, research the mechanism of nature product LC-1 oil. The results are as follows:(1) The results of bioassay about the egg of diamondback moth show that natural product LC-1 oil has very strong activity of contact and fumigation. When the dose is 5000μg/ml ,after treatment of 10 days with soaking method, and, the inhibiting rate of hatch is 86.05%; When the dose is 384μg/ml, after treatment of 10 days with feeding bottle fumigation method, and the inhibiting rate of hatch is 98.87% .(2) The results of bioassay about the larva of diamondback show that the natural produce LC-1 has the strong activity of contact and fumigation. When the dose is 5000μg/ml, after treatment of 14 days with soaking and contact method, the death rate is 82.76 %,79.31%,respectively; When the dose is 384μl/l, after treatment of 48 days with feeding bottle fumigation method, the death rate is 93.10%.(3) The results of bioassay about the larva of diamondback show that the natural produce LC-1 has the strong activity of antifeeding. When the dose is 20000μg/ml, after treatment of 24 hours, and the antifeeding rate is 95.71%, 95.87%,respectively.(4) The results of bioassay about the pupa of diamondback show that the natural produce LC-1 have the strong activity of contact and fumigation. When the dose is 5000μg/ml, after treatment of 10 days with soaking method, the death rate is 78.57%; When the dose is 384μg/ml, after treatment of 10 days with soaking method, the death rate is 96.43%.(5) The results of bioassay about corn elephant show that natural product LC-1 oil has very strong activity of fumigation. When the dose is 768 u L/L, after treatment of 72 hours processing, the death rate reaches 81.67% ; the result of bioassays about corn elephant show that the natural product LC-1 oil has not activity of toxicity, the difference of each treat is not evidence.(6) The nature product LC-1 oil and the active ingredient A of it have restrain effect to acetylcholine esterase vigor in the extracorporeal insect. When the dose is 5000μg/ml, the treat vigor of acetylcholine esterase is 0.6204 times and 0.7844 times respectively less than comparison. The nature product LC-1 oil has inhibiting effect to acetylcholine esterase in insect body inner.(7) When using a-Naphthyl acetate as bottom object, the nature product LC-1 oil had increase effect to carboxyl esterase vigor in the extracorporeal insect. When the dose is 5000μg/ml, the treat vigor of carboxyl esterase is 1.3994 times more than comparison. When usingβ-Naphthyl acetate as botton object, the nature product LC-1 oil has inhibiting effect to carboxyl esterase vigor in the extracorporeal insect. When the dose is 5000μg/ml, the relatively vigor of carboxyl esterase is 0.5885 times less than comparison. The nature product LC-1 oil had increase effect to carboxyl esterase in insect body inner.(8) 40% LC-1 ME A and B have fine activity of contact to the larva of diamondback, When the dose is 5000μg/ml, after treatment of 14 days with soaking method, the deadth rate is 93.33% , 86.21% respectively.(9)40% LC-1 ME A has good control effect, but whose effect is comparatively slow to diamondback moth. After treatment of 7 days, the controlling effect reaches the best, there is no difference between the concentration of diluting 200 and the comparison pesticide of the concentration of diluting 1000.