[ Objective ] The repellent activities and contact toxicity of extracts from Toona sinensis against Sitophilus zeamais were studied. [ Meth- od] 95% alcohol, petroleum ether and dichloromethane were selected to extrac...[ Objective ] The repellent activities and contact toxicity of extracts from Toona sinensis against Sitophilus zeamais were studied. [ Meth- od] 95% alcohol, petroleum ether and dichloromethane were selected to extract the active components from the leaves and barks of T. sinensis, respectively. And then the extracts were prepared at 0.6, 0.3, 0.15 g/ml to study the biological activity against S. zeamais in lab. [ Result J The petroleum ether extracts from the leaves of T. sinensis had significantly repellent effects on S. zeamais, but the extracts from T. sinensis with three solvents had no obvious contact toxicity against S. zeamais. [ Conclusion ] The petroleum ether extracts from S. zeamais had certain repellent activity.展开更多
The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas, Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots.. This is done for the purpose of find...The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas, Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots.. This is done for the purpose of finding a replacement for conventional insecticides which has been found to be harmful to man. The seed oil was applied topically at the rate of 0.1, 0.2, 0.3 and 0.4 mL per insect. There were a total of 20 insects per Petri-dish. There were four replicates per treatment. Insect mortality was recorded on 12 hourly basis for 48 hours. The results of insects treated with all dosage rates of C. nucifera showed a significantly higher mortality when compared with the control. In the case ofH. annus, insect mortality ranged from 40-100, 70-100, 60-100 and 80-100% and for J. curcas the result ranged from 0.0-100, 40-100, 80-100 and 80-100% for rates of 0.1, 0.2, 0.3 and 0.4 mL, respectively, from 12 hrs to 48 hrs post application. The control experiment remained at 0% level throughout the period of the experiments.展开更多
Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects, none o...Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects, none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%-100% whereas in S. zeamais, the mortality ranged from 87.5%-100% and 70%-100% in concentrations of 1 g extract＋3 ml methanol and 1 g extract＋5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract＋l 5 ml methanol had no significant lethal effect on Sitophilus zeamais.展开更多
The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this ca...The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.展开更多
Laboratory interspecific competition and grain-hosts selection experiments involving maize weevil (MW), Sitophilus zeamais (Motsch.) and larger grain borer (LGB), Prostephanus truncatus (Horn) were performed under amb...Laboratory interspecific competition and grain-hosts selection experiments involving maize weevil (MW), Sitophilus zeamais (Motsch.) and larger grain borer (LGB), Prostephanus truncatus (Horn) were performed under ambient temperature and relative humidity (25°C - 35°C and 70% - 80% relative humidity) in their major host cereal, maize grains. The species reproductive rate and grain-hosts preference were evaluated by a number of emerged adults. In combined infestation, both species competed intensively by simultaneously increasing their individuals’ emergence, 9-fold or greater than when reared alone. Even though both species simultaneously increased their progeny, S. zeamais was the dominant competitor and had a significant suppressant effect on P. truncatus. The selection result of grain-hosts showed that P. truncatus placed in the environment containing both uninfested maize grains and grains previously infested by S. zeamais, the insect prefers uninfested grains. Indeed, P. truncatus individuals’ emergences were significantly more important to uninfested grains than to infested grains. The weevil-infested grains seemed to have deterrent and detrimental effects on P. truncatus. Conversely, S. zeamais selection of grain-hosts was significantly (P = 0.0001) more attracted by P. truncatus infested grains than to uninfested grains. Sitophilus zeamais individuals’ emergences were significantly (P = 0.0008) more important to infested grains than to uninfested grains. The S. zeamais preference on grains previously infested would be stimulated by P. truncatus larval vibrations in grain.展开更多
The effects of interspecific competition on the population dynamics of four insect grain Insecp pests （ Sitophilus zeamais, Rhizopertha dominica, Tribolium castaneum and Cryptolestes ferrugineus ） was studied at 30...The effects of interspecific competition on the population dynamics of four insect grain Insecp pests （ Sitophilus zeamais, Rhizopertha dominica, Tribolium castaneum and Cryptolestes ferrugineus ） was studied at 30℃, 75% relative humidity. A regression analysis of the population dynamics was conducted. The results showed that population growth of S. zeamais , R. dominica, T. castaneum and C. ferrugineus was restrained under mixed rearing. Population growth of T. castaneum and C. ferrugineus was remarkably accelerated when they coexisted with S. zeamais or R. dominica, while that of S. zeamais and R. dominica was restrained to some extent. Regression analysis results showed that the population growth potential of S. zeamais was the largest and that of C. ferrugineus was the smallest, and the changing trends of population growth rates were not distinct.展开更多
[Objective] The study aimed to provide the theoretical basis for the development of Saponins isolated from Sapindus mukurossi in the application of pesticides and lay the foundation for the development and utilization...[Objective] The study aimed to provide the theoretical basis for the development of Saponins isolated from Sapindus mukurossi in the application of pesticides and lay the foundation for the development and utilization of Sapindus species resources in Yunnan province. [ Method] Saponine from S. mukurossi was extracted by the methods of dipping, feed mixed with pesticide, unlimited feeding, and conducted indoor toxicity determination on Plutella xylostella （Linnaeus）, Sitophilus zeamais motschulsky and Drosophila. [ Result] Saponin had no poisoning activity on maize weevil, while it had certain biological activity on diamondback moth and fruit fly, but it had high activity on fruit fly, when the concentration was 50 mg/ml, mortality was 100% at 72 h, LCso was 4.06 mg/ml at 72 h, LTso was 30.19 h when the concentration was 25.000 mg/ml. [Conclusion] Saponins from S. mukurossi could be develooed and utilized as the material for botanical eesticide.展开更多
Calamusenone [3,8-dimethyl-5-（1-methylethylidene）- 1,2,3,4,5,6,7,8-octa- hydroazulene-6-one, C15H22O] from Acorus gramineus Soland rhizome was tested in the laboratory for its insecticidal activities against adults ...Calamusenone [3,8-dimethyl-5-（1-methylethylidene）- 1,2,3,4,5,6,7,8-octa- hydroazulene-6-one, C15H22O] from Acorus gramineus Soland rhizome was tested in the laboratory for its insecticidal activities against adults of Sitophilus zeamais Motsch. and Rhizopertha dominica （Fab.）, using dry film contact and fumigation methods. Responses varied with insect species, dosage and exposure time. In the dry film contact experiment, the highest insecticidal effects of calamusenone against S. zeamais and R. dominica adults were produced at 170.32μg/cm2 after treatment for 72 h, with 96.2% and 98.7% mortalities, respectively. The median lethal concentration （LC50） （72 h） values of calamusenone against S. zeamais and R. dominica adults were 67.00 μg/cm2 and 77.30 μg/cm2, respectively. As a potential fumigant, calamusenone showed moderate insecticidal effect on the adults of S. zeamais and R. dominica in fumigation experiment, with their LC50 （120 h） values of 125.71μL/L and 93.64μL/L respectively. Calamusenone isolated from A. gramineus rhizome showed promise as a novel pesticide candidate for stored-product pest control.展开更多
基金Supported by Scientific Research Foundation of China West Normal University(07B006)~~
文摘[ Objective ] The repellent activities and contact toxicity of extracts from Toona sinensis against Sitophilus zeamais were studied. [ Meth- od] 95% alcohol, petroleum ether and dichloromethane were selected to extract the active components from the leaves and barks of T. sinensis, respectively. And then the extracts were prepared at 0.6, 0.3, 0.15 g/ml to study the biological activity against S. zeamais in lab. [ Result J The petroleum ether extracts from the leaves of T. sinensis had significantly repellent effects on S. zeamais, but the extracts from T. sinensis with three solvents had no obvious contact toxicity against S. zeamais. [ Conclusion ] The petroleum ether extracts from S. zeamais had certain repellent activity.
文摘The insecticidal effect of four dosage rates of three botanicals namely Jatropha curcas, Heliathus annus and Cocos nucifera was tested on the maize weevil Sitophilus zeamais Mots.. This is done for the purpose of finding a replacement for conventional insecticides which has been found to be harmful to man. The seed oil was applied topically at the rate of 0.1, 0.2, 0.3 and 0.4 mL per insect. There were a total of 20 insects per Petri-dish. There were four replicates per treatment. Insect mortality was recorded on 12 hourly basis for 48 hours. The results of insects treated with all dosage rates of C. nucifera showed a significantly higher mortality when compared with the control. In the case ofH. annus, insect mortality ranged from 40-100, 70-100, 60-100 and 80-100% and for J. curcas the result ranged from 0.0-100, 40-100, 80-100 and 80-100% for rates of 0.1, 0.2, 0.3 and 0.4 mL, respectively, from 12 hrs to 48 hrs post application. The control experiment remained at 0% level throughout the period of the experiments.
文摘Insecticidal effects of different doses of the dust and methanol extracts of Garcinia kolae on Callosobruchus maculatus and Sitophilus zeamais were tested. The dust had no significant effect on the two insects, none of them died even at 3 d after treatment. The methanol extracts, however, had rapid lethal effects on both C. maculatus and S. zeamais. The mortality of C. maculatus by the lowest concentration of methanol extracts ranged from 95%-100% whereas in S. zeamais, the mortality ranged from 87.5%-100% and 70%-100% in concentrations of 1 g extract＋3 ml methanol and 1 g extract＋5 ml methanol, respectively, from 24 to 48 h. The least concentration of 1 g extract＋l 5 ml methanol had no significant lethal effect on Sitophilus zeamais.
文摘The remarkable push of technologies increasingly recommends materials for their constructions.Hence the extraction of alumina is for different uses.The exploitation of bauxite pollutes the surrounding areas in this case the discharge of mud wheel.Furthermore,the excessive use of dangerous conventional synthetic insecticides continues to be in circulation in Cameroon despite the known adverse effects.These problems lead us to formulate bio insecticides from rejection of the extraction of alumina and extracts of S.aromaticum and Citrus sinensis which respectively offer us essential oils eugenol and limonene having insecticidal properties against the main insects,pests of corn stocks,Sitophilus zeamais.From the kinetic point of view of the adsorption of the extracts of eugenol,limonene and their association by the red mud,the adsorption curve shows that the Eu/Li mixture(30/70)is better by 0.36 mg/g during the 24 h.The results showed a high toxicity of the Eu-Li binary mixture of ratio 30/70 with respective mortality rates of 95.88%after 8 days of exposure to the concentration of 5 mL/L on the adults of Sitophilus zeamais.The other composites induce an average rate of 80%.The results from the physicochemical analysis of corn before and after treatment with formulated insecticides showed a slight loss in nutritional quality of 14.90%in ash,12.5%in protein,16.14%in lipids and 13.63%in total sugars for 180 days.The powdery formulation from red mud and Eu-Li(30/70)mixture can therefore ensure the protection of corn stocks against Sitophilus zeamais in a farming environment.
文摘Laboratory interspecific competition and grain-hosts selection experiments involving maize weevil (MW), Sitophilus zeamais (Motsch.) and larger grain borer (LGB), Prostephanus truncatus (Horn) were performed under ambient temperature and relative humidity (25°C - 35°C and 70% - 80% relative humidity) in their major host cereal, maize grains. The species reproductive rate and grain-hosts preference were evaluated by a number of emerged adults. In combined infestation, both species competed intensively by simultaneously increasing their individuals’ emergence, 9-fold or greater than when reared alone. Even though both species simultaneously increased their progeny, S. zeamais was the dominant competitor and had a significant suppressant effect on P. truncatus. The selection result of grain-hosts showed that P. truncatus placed in the environment containing both uninfested maize grains and grains previously infested by S. zeamais, the insect prefers uninfested grains. Indeed, P. truncatus individuals’ emergences were significantly more important to uninfested grains than to infested grains. The weevil-infested grains seemed to have deterrent and detrimental effects on P. truncatus. Conversely, S. zeamais selection of grain-hosts was significantly (P = 0.0001) more attracted by P. truncatus infested grains than to uninfested grains. Sitophilus zeamais individuals’ emergences were significantly (P = 0.0008) more important to infested grains than to uninfested grains. The S. zeamais preference on grains previously infested would be stimulated by P. truncatus larval vibrations in grain.
基金重庆市科委攻关项目(CSTC,2004A C 1003) 重庆市教委科学技术研究资助项目(KJ030204)~~
文摘The effects of interspecific competition on the population dynamics of four insect grain Insecp pests （ Sitophilus zeamais, Rhizopertha dominica, Tribolium castaneum and Cryptolestes ferrugineus ） was studied at 30℃, 75% relative humidity. A regression analysis of the population dynamics was conducted. The results showed that population growth of S. zeamais , R. dominica, T. castaneum and C. ferrugineus was restrained under mixed rearing. Population growth of T. castaneum and C. ferrugineus was remarkably accelerated when they coexisted with S. zeamais or R. dominica, while that of S. zeamais and R. dominica was restrained to some extent. Regression analysis results showed that the population growth potential of S. zeamais was the largest and that of C. ferrugineus was the smallest, and the changing trends of population growth rates were not distinct.
基金Supported by National Natural Science Foundation of China(30660108)~~
文摘[Objective] The study aimed to provide the theoretical basis for the development of Saponins isolated from Sapindus mukurossi in the application of pesticides and lay the foundation for the development and utilization of Sapindus species resources in Yunnan province. [ Method] Saponine from S. mukurossi was extracted by the methods of dipping, feed mixed with pesticide, unlimited feeding, and conducted indoor toxicity determination on Plutella xylostella （Linnaeus）, Sitophilus zeamais motschulsky and Drosophila. [ Result] Saponin had no poisoning activity on maize weevil, while it had certain biological activity on diamondback moth and fruit fly, but it had high activity on fruit fly, when the concentration was 50 mg/ml, mortality was 100% at 72 h, LCso was 4.06 mg/ml at 72 h, LTso was 30.19 h when the concentration was 25.000 mg/ml. [Conclusion] Saponins from S. mukurossi could be develooed and utilized as the material for botanical eesticide.
文摘Calamusenone [3,8-dimethyl-5-（1-methylethylidene）- 1,2,3,4,5,6,7,8-octa- hydroazulene-6-one, C15H22O] from Acorus gramineus Soland rhizome was tested in the laboratory for its insecticidal activities against adults of Sitophilus zeamais Motsch. and Rhizopertha dominica （Fab.）, using dry film contact and fumigation methods. Responses varied with insect species, dosage and exposure time. In the dry film contact experiment, the highest insecticidal effects of calamusenone against S. zeamais and R. dominica adults were produced at 170.32μg/cm2 after treatment for 72 h, with 96.2% and 98.7% mortalities, respectively. The median lethal concentration （LC50） （72 h） values of calamusenone against S. zeamais and R. dominica adults were 67.00 μg/cm2 and 77.30 μg/cm2, respectively. As a potential fumigant, calamusenone showed moderate insecticidal effect on the adults of S. zeamais and R. dominica in fumigation experiment, with their LC50 （120 h） values of 125.71μL/L and 93.64μL/L respectively. Calamusenone isolated from A. gramineus rhizome showed promise as a novel pesticide candidate for stored-product pest control.
