Distribution of horizontal boom produced droplets downwards into maize canopies at flowering period and its effects on the efficacies of emamectin benzoate, lambda-cyhalothrin and chlorantraniliprole against the secon...Distribution of horizontal boom produced droplets downwards into maize canopies at flowering period and its effects on the efficacies of emamectin benzoate, lambda-cyhalothrin and chlorantraniliprole against the second generation of Asian corn borer （ACB） larvae and their toxicity to spiders were studied. When insecticides were sprayed downwards into the maize canopies, randomly filtering out droplets by upper leaves led to great variations of droplet coverage and density within the canopies. Consequently, the efficacies of lambda-cyhalothrin and emamectin benzoate against ACB larvae were decreased because of randomly filtering out droplets by upper leaves. But field investigation showed that lambda-cyhalothrin was extremely toxic to hunting spiders, Xysticus ephippiatus, and not suitable to IPM programs in regulation of the second generation of ACB. Therefore, randomly filtering out droplets by upper leaves decreased lambda-cyhalothrin＇s efficacy against ACB larvae, but did little to decrease its toxicity to X. ephippiatus. Amamectin benzoate can reduce the populations of X. ephippiatus by 58.1-61.4%, but the populations can recover at the end of the experiment. Chlorantraniliprole was relatively safe to X. ephippiatus. It only reduced the populations of X. ephippiatus by 22.3-33.0%, and the populations can totally recover 9 d after application.展开更多
Objective and Methods Insecticide use, grower preferences regarding genetically engineered (GE) corn resistant to com rootworm (CRW), and the health effects of using various CRW insecticides (organophosphates, pyrethr...Objective and Methods Insecticide use, grower preferences regarding genetically engineered (GE) corn resistant to com rootworm (CRW), and the health effects of using various CRW insecticides (organophosphates, pyrethroids, fipronil and carbamates) are reviewed for current and future farm practices. Results Pest damage to corn has been reduced only one-third by insecticide applications. Health costs from insecticide use appear significant, but costs attributable to CRW control are not quantifiable from available data. Methods reducing health-related costs of insecticide-based CRW control should be evaluated. As a first step, organophosphate insecticide use has been reduced as they have high acute toxicity and risk of long-term neurological consequences. A second step is to use agents which more specifically target the CRW. Conclusion Whereas current insecticides may be poisonous to many species of insects, birds, mammals and humans, a protein derived from Bacillus thurigiensis and produced in plants via genetic modification can target the specific insect of CRW (Coleoptra), sparing other insect and non-insect species from injury.展开更多
Thiacloprid has been banned in many European countries for its toxicity, but is nevertheless still used outside the EU. Using the ant Myrmica sabuleti as a model organism, we sought a concentration of thiacloprid that...Thiacloprid has been banned in many European countries for its toxicity, but is nevertheless still used outside the EU. Using the ant Myrmica sabuleti as a model organism, we sought a concentration of thiacloprid that would be low in environmental impact, but nonetheless harmful to an insect. Assessed on ten biological traits, a sub-lethal 2 μg/L concentration in the sugar water diet of the ants impacted their locomotion and other motor-linked behavioral traits such as orientation, moving on an unfamiliar device, moving on a rough surface, brood caring and progressing along a twist and turns path. Sensory perception appeared unaffected. Behaviors involving cognition or related in some way to it, such as social relationships, ability to leave an enclosure, learning and memory also appeared unaffected, but their outcomes could be entangled with those of locomotor impairment. The effect of thiacloprid on locomotion vanished in about 30 hours. Adverse effects were still present with the 0.1 and 0.01 μg/L concentrations, but at a lower level. Partial physiological adaptation at the individual level occurred for the 2 μg/L concentration, less so for 0.1 μg/L and not for 0.01 μg/L. Thiacloprid should thus be used at the lowest still active concentration producing a significant damaging behavioral effect with no physiological adaptation. This concentration remains to be specifically defined for targeted pest species.展开更多
基金supported by the China Agriculture Research System(CARS-02)the Public Welfare Project from Ministry of Agriculture of the People’s Republic of China(201203025)
文摘Distribution of horizontal boom produced droplets downwards into maize canopies at flowering period and its effects on the efficacies of emamectin benzoate, lambda-cyhalothrin and chlorantraniliprole against the second generation of Asian corn borer （ACB） larvae and their toxicity to spiders were studied. When insecticides were sprayed downwards into the maize canopies, randomly filtering out droplets by upper leaves led to great variations of droplet coverage and density within the canopies. Consequently, the efficacies of lambda-cyhalothrin and emamectin benzoate against ACB larvae were decreased because of randomly filtering out droplets by upper leaves. But field investigation showed that lambda-cyhalothrin was extremely toxic to hunting spiders, Xysticus ephippiatus, and not suitable to IPM programs in regulation of the second generation of ACB. Therefore, randomly filtering out droplets by upper leaves decreased lambda-cyhalothrin＇s efficacy against ACB larvae, but did little to decrease its toxicity to X. ephippiatus. Amamectin benzoate can reduce the populations of X. ephippiatus by 58.1-61.4%, but the populations can recover at the end of the experiment. Chlorantraniliprole was relatively safe to X. ephippiatus. It only reduced the populations of X. ephippiatus by 22.3-33.0%, and the populations can totally recover 9 d after application.
文摘Objective and Methods Insecticide use, grower preferences regarding genetically engineered (GE) corn resistant to com rootworm (CRW), and the health effects of using various CRW insecticides (organophosphates, pyrethroids, fipronil and carbamates) are reviewed for current and future farm practices. Results Pest damage to corn has been reduced only one-third by insecticide applications. Health costs from insecticide use appear significant, but costs attributable to CRW control are not quantifiable from available data. Methods reducing health-related costs of insecticide-based CRW control should be evaluated. As a first step, organophosphate insecticide use has been reduced as they have high acute toxicity and risk of long-term neurological consequences. A second step is to use agents which more specifically target the CRW. Conclusion Whereas current insecticides may be poisonous to many species of insects, birds, mammals and humans, a protein derived from Bacillus thurigiensis and produced in plants via genetic modification can target the specific insect of CRW (Coleoptra), sparing other insect and non-insect species from injury.
文摘Thiacloprid has been banned in many European countries for its toxicity, but is nevertheless still used outside the EU. Using the ant Myrmica sabuleti as a model organism, we sought a concentration of thiacloprid that would be low in environmental impact, but nonetheless harmful to an insect. Assessed on ten biological traits, a sub-lethal 2 μg/L concentration in the sugar water diet of the ants impacted their locomotion and other motor-linked behavioral traits such as orientation, moving on an unfamiliar device, moving on a rough surface, brood caring and progressing along a twist and turns path. Sensory perception appeared unaffected. Behaviors involving cognition or related in some way to it, such as social relationships, ability to leave an enclosure, learning and memory also appeared unaffected, but their outcomes could be entangled with those of locomotor impairment. The effect of thiacloprid on locomotion vanished in about 30 hours. Adverse effects were still present with the 0.1 and 0.01 μg/L concentrations, but at a lower level. Partial physiological adaptation at the individual level occurred for the 2 μg/L concentration, less so for 0.1 μg/L and not for 0.01 μg/L. Thiacloprid should thus be used at the lowest still active concentration producing a significant damaging behavioral effect with no physiological adaptation. This concentration remains to be specifically defined for targeted pest species.
