| Bioactivities of extracts from Xinjiang 30 plants were tested against Aphis gossypii Glover, Tetranychus cinnarinus Boisduva, Bemisia tabaci (Gennadius) , and the security of some extracts to nature enemies were detected as well, meantime, the action mode and insecticidal mechanism were discussed initially. The main findings are as the following:1. High bioactivities were observed with plant1 extracts against Aphis gossypii Glover and Tetranychus cinnarinus Boisduva but Bemisia tabaci (Gennadius).(1) The extraction rates are different between different parts of plant1in different methods and solvents. 24% of the highest extraction rate was from 0828T1 in methanol cold-dip method; 22% of the highest extraction rate was from 0924T6 in Ultrasonic extract method; 14% of the highest extraction rate was from 0903T2 in solvent of butanol.(2) Methanol extracts of 0912T5,1011T7,0905T3 and 0903T2 showed high contacted bioactivities to Aphis gossypii Glover, the corrected mortalities (24h) were all above 97.48%. LC50 were 1.018g/L,2.642g/L,2.363g/L and 1.728g/L,respectively.(3) 0903T2 extracts in different solvents under concentration of 12.0g/L-56.0g/L showed high contacted bioactivities to Aphis gossypii Glover, the corrected mortalities (24h) were all above 97.16%-100%. Contacted bioactivities of extracts from chloroform, petroleum ether and Ethyl Acetate showed better activities than the others, LC50 were 0.212g/L,0.261g/L and 0.343g/L, respectively.(4)Significant differences were found in contacted bioactivities to Aphis gossypii Glover between extracts of 0903T2 mehanol extracts in different solvents, the corrected mortalities (24h) reached to 62.59%-88.09%. 4.0g/L Ethyl Acetate extracts, 1.6g/L chloroform extracts, 4.0g/L petroleum ether extracts showed better activities than the others, the corrected mortalities (24h) were 77.09%,63.42% and 62.59%, LC50 were 0.501g/L,0.898g/L and 2.174g/L, respectively.No significant differences were found in contacted bioactivities to Aphis gossypii Glover between extracts of 0910T4 mehanol extracts in different solvents, the corrected mortalities (24h) reached to 80.92%-100%. 12.0g/L Ethyl Acetate extracts showed the highest activities among all of extracts from different solvents, LC50 was 0.803g/L.(5) Most of methanol extracts from plant1 showed little detained membrane and osmosis bioactivities to Aphis gossypii Glover except 0828T1 methanol extracts, the corrected mortalities (24h) was 65.9% only.(6) 0903T2 mehanol extracts showed lower bioactivities to Bemisia tabaci in the method of leaf-dip bioassay, the corrected mortalities (48h) in the highest concentration (36g/L) was 45.56% only, whereas there are almost no any bioactivities were showed with treatments in low concentration.(7) Methanol extracts of 0912T5,1011T7,0905T and 0903T2 showed high contacted bioactivities to Tetranychus cinnarinus Boisduva, the corrected mortalities (24h) were all above 90%. 0910T4 methanol extracts showed high acaricidal activity with LC50of 0.554g/L.2. High bioactivities were displayed with plant 2 extracts against Aphis gossypii Glover and Tetranychus cinnarinus Boisduva but Bemisia tabaci (Gennadius). (1) The highest extraction rate, 28%, was from 1019W1 in methanol, the second was 1115W7 with 13% extraction rate.(2) All methanol extracts from plant2 under concentration of 14.0g/L-56.0g/L showed high contacted bioactivities to Aphis gossypii Glover, the corrected mortalities (24h) were all above 95% except the extracts from 1023W2 and 1109W5 which were not tested.(3) Most of methanol extracts from plant1 showed little detained membrane and osmosis bioactivities to Aphis gossypii Glover, the corrected mortalities (24h) were 1.69%-41.46% only.(4) High contacted bioactivities to Aphis gossypii Glover were showed from extracts of 1025W3 methanol extracts in different solvents except extract from Ethyl Acetate, the corrected mortalities (24h) were all above 93.41%-100%. Extracts from chloroform and petroleum ether showed high activities in LC50of 0.251 g/L and 0.672g/L, respectively,(5) 1025W3 mehanol extracts showed lower bioactivities to adults of Bemisia tabaci in leaf-dip bioassay, the corrected mortalities (48h) in the highest concentration (40g/L) was 51.43% only, whereas there were almost no any bioactivities were showed with treatments in low concentration.(6) Plant2 methanol extracts showed high contacted bioactivities to Tetranychus cinnarinus Boisduva, especially1019W1 and 1109W5, the corrected mortalities (24h) were all above 90%.3. Extracts from the other 30 plants showed significant insecticidal activities to cotton pest.(1) High methanol extraction rates, 20.7%-34%,were obtained in plants of 1228T,0319S1,0115L,0108D6,0126S,1105X at the same initial material of 10g, whereas extraction rate in plants of 1210Y3,1212Y4,0321S2 were less than 5%.(2) All methanol extracts from other 30 tested plants showed high contacted bioactivities to Aphis gossypii Glover, especially the plants of 1210Y3,1212Y4 and 0321S2, the corrected mortalities (24h) were reached to 94.95%-100% under concentration of12.0g/L-16.0g/L.(3) Most of methanol extracts from other 30 tested plants showed little detained membrane and osmosis bioactivities to Aphis gossypii Glover, the highest corrected mortalities (24h) were 30.36% only.(4) Most of methanol extracts from other 30 tested plants showed high contacted bioactivities to Tetranychus cinnarinus Boisduva, excepted plants of 1208Y,0108D6,0113B,0117L,0211L and 1119D, the corrected mortalities (24h) were all above 90%-100% in tested plants .4. Both extracts from plant1 and plant2 are safe to natural enemies.(1) Lower contacted bioactivities were obtained from 0903T2 methanol extracts to natural enemies, Coccinella septempunctata L. and Adonia Variegata(Goeze), the corrected mortalities (48h) were 12.47% and 23.08% at the highest concentration of 40g/L, respectively, and the corrected mortalities decreased distinctly along with the concentration decreasing, no significant differences were found in mortalities to compare with control. There are significant differences were found in contacted bioactivities to Adonia Variegata(Goeze) between 0903T2 methanol extract and pesticides, Confidor and thiodan, the mortality was relatively lower when the concentration of 0903T2 methanol extract is 10 times of Confidor and thiodan. (2) Results suggested that1025W3 methanol extract is safe to natural enemies. Lower contacted bioactivities were obtained from 1025W3 methanol extract to Adonia Variegata(Goeze) , the corrected mortalities (48h) were 25.09% at the highest concentration of 40g/L. There are significant differences were found in contacted activities to Adonia Variegata(Goeze) between 1025W3 methanol extract and Confidor as well as thiodan.5. Results suggested that the main action of plant extracts are contacted bioactivities. Body fluid extravasated and then led to the body dry after contacted with plant extracts was the most important mechanism by the changes on the body back as well as the dying process of tested insects.6. Multi-compound exhibited bioactivities from plant1 and plant2(1) Alkaloids, coumarins and flavonoids are main components in 0903T2 and 0910T4.(2) Alkaloids, coumarins, flavonoids, phenols and tannins are main components in 1025W3.
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