Joint toxicity of Beauveria bassiana and two insect growth regulators, methoxyfenozide and hexaflumuron, on beet annywonn larvae, Spodoptera exigua （ Htthner）, were investigated. An obvious synergism effect of the t...Joint toxicity of Beauveria bassiana and two insect growth regulators, methoxyfenozide and hexaflumuron, on beet annywonn larvae, Spodoptera exigua （ Htthner）, were investigated. An obvious synergism effect of the two insect growth regulators with B. beauveria was observed. When the insect growth regulators at LC50 concentrations （25 × 10^-6 g/L for methoxyfenozide and 1 000 × 10^ -6 g/L for hexaflumuren） were mixed with B. bassiana at the volume ratio of 4： 1, the mixtures achieved the best efficacy. The co-toxicity co-efficient （CTC） of methexyfenozide and B. bass/ana was 285, and that of hexaflumuron and B. bass/ana was 208. Scanning electron microscope observation of the longitudinal section of S. exigua revealed obviously different patterns of integument in different treatment groups.展开更多
Insect growth regulators play an important role in integrated pest management strategies.The FGLa–allatostatins（ASTs）are a family of neuropeptides that can inhibit juvenile hormone（JH）biosynthesis by the corpora ...Insect growth regulators play an important role in integrated pest management strategies.The FGLa–allatostatins（ASTs）are a family of neuropeptides that can inhibit juvenile hormone（JH）biosynthesis by the corpora allata（CA）of Diploptera punctata in vitro,are regarded as insect growth regulator candidates.In the search for new potential mimics and to explore the effect of linker length on inhibiting JH biosynthesis,a series of AST analogs were synthesized by modifying the linker of K24,which was found to have a significant effect on JH biosynthesis in vitro in our previous study.Functional evaluation demonstrated that all the target compounds can activate the Dippu-Ast R,albeit with different potencies.Analog L6 with the longest linker（n=5）,exhibited not only a promising effect on inhibition of JH biosynthesis both in vitro and in vivo,but also good activity in inhibiting basal oocyte growth.Structure–activity relationships（SAR）studies showed that longer linkers provided greater contribution to activity.展开更多
Tebufenozide,an efficient insect growth regulator(IGR)against lepidopteran pests,presents a novel mode of action with minimal non-target impact.By competing with ecdysteroids for ecdysone receptor(EcR)binding,it regul...Tebufenozide,an efficient insect growth regulator(IGR)against lepidopteran pests,presents a novel mode of action with minimal non-target impact.By competing with ecdysteroids for ecdysone receptor(EcR)binding,it regulates insect growth precisely.This study explores tebufenozide's potential as a multitarget IGR,targeting both EcR and Ostrinia furnacalis chitinase I(OfChtI).The inhibitory activity against OfChtI is comparable to that of substrates(GlcNAc)5,with an IC50 of 45.77μM.Our computational findings indicate that tebufenozide binds at the subsite1 to t1 of OfChtI through various interactions.Notably,tebufenozide establishes a pi-pi interaction with the flipped sidechain of Trp107,enabling tebufenozide to deeply penetrate into the S1 pocket,thereby obstructing substrate binding to OfChtI.These insights highlight the potency of multitarget strategies,laying the groundwork for innovative IGR designs that offer comprehensive pest management solutions.展开更多
QSAR studies of 27 diacyl-hydrazine derivatives containing furan rings were conducted and compared with the DFT method and AM1-MOPAC method.q2 values of 0.61 and 0.40 validated the predictability and reliability of eq...QSAR studies of 27 diacyl-hydrazine derivatives containing furan rings were conducted and compared with the DFT method and AM1-MOPAC method.q2 values of 0.61 and 0.40 validated the predictability and reliability of eq.(5)from the DFT method were higher than those of eq.(6)from the AM1-MOPAC method.The DFT-optimized conformations and ESP-fitting charges of the target compounds were also used for 3D-QSAR analysis,including CoMFA and CoMSIA.The leave-one-out cross-validation correlation coefficient and the good correlation between the predicted and experimental activities of excluded test compounds revealed that CoMFA and CoMSIA models were robust.The QSAR results were consistent with the 3D-QSAR results,indicating that the electrostatic and hydrophobic properties of the target compounds were significant to the biological activity.These models are useful tools for predicting the larvicidal activities of new compounds and designing new specific insect growth regulators.展开更多
The aim of this study was to investigate the possibility of eradicating the red imported fire ant, Solenopsis invicta Buren, in the hot, humid and rainy conditions of northern Taiwan. Thirteen hectares of the Shihmen ...The aim of this study was to investigate the possibility of eradicating the red imported fire ant, Solenopsis invicta Buren, in the hot, humid and rainy conditions of northern Taiwan. Thirteen hectares of the Shihmen Reservoir have been infected with these ants, with a total of 1 578 mounds. Pyriproxyfen was applied at a rate of 2 kg/hectare each season, for a total of four seasons. Surveys using visual examination, bait traps, as well as the population index method showed that the brood, the reproductive ants, and the worker ants within the nests were all significantly reduced 1 month after the first application of pyriproxyfen. Four months after the initial application there were no more brood or reproductive ants. After 8 months there were no longer any active mounds left, and 12 months later there were no more worker ants. After monitoring for 1 more year, it was ascertained that the red imported fire ants were eradicated. The percentages of decrease after 2, 4 and 6 months of treatment were 57.4%, 80.5%, and 98.2%, respectively.展开更多
基金Supported by National Key Technology Support Program(2012BAD19B01)
文摘Joint toxicity of Beauveria bassiana and two insect growth regulators, methoxyfenozide and hexaflumuron, on beet annywonn larvae, Spodoptera exigua （ Htthner）, were investigated. An obvious synergism effect of the two insect growth regulators with B. beauveria was observed. When the insect growth regulators at LC50 concentrations （25 × 10^-6 g/L for methoxyfenozide and 1 000 × 10^ -6 g/L for hexaflumuren） were mixed with B. bassiana at the volume ratio of 4： 1, the mixtures achieved the best efficacy. The co-toxicity co-efficient （CTC） of methexyfenozide and B. bass/ana was 285, and that of hexaflumuron and B. bass/ana was 208. Scanning electron microscope observation of the longitudinal section of S. exigua revealed obviously different patterns of integument in different treatment groups.
基金supported by the National Natural Science Foundation of China (No. 21372257)the National Basic Research Program of China (973 Program, No. 2010CB126104)+1 种基金the Natural Sciences and Engineering Research Council of Canadasupported by China Scholarship Council (CSC) to study in the laboratory of SST at University of Toronto,Canada
文摘Insect growth regulators play an important role in integrated pest management strategies.The FGLa–allatostatins（ASTs）are a family of neuropeptides that can inhibit juvenile hormone（JH）biosynthesis by the corpora allata（CA）of Diploptera punctata in vitro,are regarded as insect growth regulator candidates.In the search for new potential mimics and to explore the effect of linker length on inhibiting JH biosynthesis,a series of AST analogs were synthesized by modifying the linker of K24,which was found to have a significant effect on JH biosynthesis in vitro in our previous study.Functional evaluation demonstrated that all the target compounds can activate the Dippu-Ast R,albeit with different potencies.Analog L6 with the longest linker（n=5）,exhibited not only a promising effect on inhibition of JH biosynthesis both in vitro and in vivo,but also good activity in inhibiting basal oocyte growth.Structure–activity relationships（SAR）studies showed that longer linkers provided greater contribution to activity.
基金financially supported by the National Natural Science Foundation of China(No.22177132 and 21977114).
文摘Tebufenozide,an efficient insect growth regulator(IGR)against lepidopteran pests,presents a novel mode of action with minimal non-target impact.By competing with ecdysteroids for ecdysone receptor(EcR)binding,it regulates insect growth precisely.This study explores tebufenozide's potential as a multitarget IGR,targeting both EcR and Ostrinia furnacalis chitinase I(OfChtI).The inhibitory activity against OfChtI is comparable to that of substrates(GlcNAc)5,with an IC50 of 45.77μM.Our computational findings indicate that tebufenozide binds at the subsite1 to t1 of OfChtI through various interactions.Notably,tebufenozide establishes a pi-pi interaction with the flipped sidechain of Trp107,enabling tebufenozide to deeply penetrate into the S1 pocket,thereby obstructing substrate binding to OfChtI.These insights highlight the potency of multitarget strategies,laying the groundwork for innovative IGR designs that offer comprehensive pest management solutions.
基金supported by the National Natural Science Foundation of China(20802089)the National Basic Research Program of China(2010CB126104)+2 种基金the Research Fund for the Key Laboratory of Pesticide&Chemical Biology(Huazhong Normal University)Ministry of Education(200803A02)the Research Fund for the State Key Laboratory of Elemento-Organic Chemistry,Nankai University(0805)
文摘QSAR studies of 27 diacyl-hydrazine derivatives containing furan rings were conducted and compared with the DFT method and AM1-MOPAC method.q2 values of 0.61 and 0.40 validated the predictability and reliability of eq.(5)from the DFT method were higher than those of eq.(6)from the AM1-MOPAC method.The DFT-optimized conformations and ESP-fitting charges of the target compounds were also used for 3D-QSAR analysis,including CoMFA and CoMSIA.The leave-one-out cross-validation correlation coefficient and the good correlation between the predicted and experimental activities of excluded test compounds revealed that CoMFA and CoMSIA models were robust.The QSAR results were consistent with the 3D-QSAR results,indicating that the electrostatic and hydrophobic properties of the target compounds were significant to the biological activity.These models are useful tools for predicting the larvicidal activities of new compounds and designing new specific insect growth regulators.
文摘The aim of this study was to investigate the possibility of eradicating the red imported fire ant, Solenopsis invicta Buren, in the hot, humid and rainy conditions of northern Taiwan. Thirteen hectares of the Shihmen Reservoir have been infected with these ants, with a total of 1 578 mounds. Pyriproxyfen was applied at a rate of 2 kg/hectare each season, for a total of four seasons. Surveys using visual examination, bait traps, as well as the population index method showed that the brood, the reproductive ants, and the worker ants within the nests were all significantly reduced 1 month after the first application of pyriproxyfen. Four months after the initial application there were no more brood or reproductive ants. After 8 months there were no longer any active mounds left, and 12 months later there were no more worker ants. After monitoring for 1 more year, it was ascertained that the red imported fire ants were eradicated. The percentages of decrease after 2, 4 and 6 months of treatment were 57.4%, 80.5%, and 98.2%, respectively.
