Spruce budworm （Choristoneura fumiferana （Clemens）） is one of the most serious forest insect pests in North America. Laboratory bioassays were performed to determine the lethal doses and lethal time of pyrethrins ...Spruce budworm （Choristoneura fumiferana （Clemens）） is one of the most serious forest insect pests in North America. Laboratory bioassays were performed to determine the lethal doses and lethal time of pyrethrins （a botanical insecticide） on 4th instar larvae of spruce bud-worm using larval dip assay. Results show that the LT50 values（time of 50% larval mortality）for spruce budworm at the pyrethrins concentra-tions of 12.5, 25, 50, 100, and 200 μg·L-1 were 94.78, 45.54, 20.36, 14.39 and 11.37 h, respectively. The percentage of cumulative mortality at the pyrethrins concentrations of 12.5, 25, 50, 100, 200 μg·L-1 was approxi-mately 50%, 67%, 93%, 100% and 100% within 120 h, respectively. The LC50 value （concentration of 50% larval mortality） for the 4th instar lar-vae was 16.1μg·L-1. Thus, larval mortality of spruce budworm increased in a concentration-dependent manner, and lethal time decreased with increasing pyrethin concentrations. These findings suggest that pyrethrins have a potential in controlling spruce budworm populations.展开更多
Apolygus lucorum（Meyer-Dür.） and Erythroneura apicalis（Nawa） are important pests that affect the quality and the yield of grapevine and cause huge economic losses. This paper focuses on the selection of effec...Apolygus lucorum（Meyer-Dür.） and Erythroneura apicalis（Nawa） are important pests that affect the quality and the yield of grapevine and cause huge economic losses. This paper focuses on the selection of effective botanical pesticides to control A. lucorum and E. apicalis. This experiment explores the effect of several botanical pesticides for A. lucorum and E. apicalis, including the 0.5% veratrine, the0.6% Oxygen·Lactone agent, the 5% natural pyrethrin, the composite neem pesticide, the rotenone and the composite nicotine. The 0.5% veratrine shows a stable control efficacy, which is higher than 60% in Chengdu, while the composite nicotine shows the highest efficacy against A. lucorum, which is above 70%. In Yinchuan,the 0.5% veratrine shows the highest efficacy, against the first generation adults and the second generation larvae of E. apicalis, while the 5% natural pyrethrin shows 100% control efficacy against E. apicalis in Nanjiang. The 0.5% veratrine and the composite neem could be used as effective pesticides to control A. lucorum and the 5% natural pyrethrin can be used to control E. apicalis. They could be widely used in the production of pollution-free grapes.展开更多
Three commercial neem [Azadirachta indica A. Juss (Meliaceae)]-basedinsecticides, Agroneem, Ecozin, and Neemix, and a non-commercial neem leaf powder, were evaluatedfor oviposition deterrence, antifeedant effect on la...Three commercial neem [Azadirachta indica A. Juss (Meliaceae)]-basedinsecticides, Agroneem, Ecozin, and Neemix, and a non-commercial neem leaf powder, were evaluatedfor oviposition deterrence, antifeedant effect on larvae, and toxicity to eggs and larvae of thebeet armyworm, Spodoptera exigua (Huebner) (Lepidoptera: Noctuidae), on cotton leaves in thelaboratory. Oviposition deterrence in no-choice, and two- and five-choice assays, was observed forthe neem-based insecticide treatments when compared with a non-treated control. Neem-basedinsecticides also deterred feeding by beet armyworm larvae. Direct contact with neem-basedinsecticides decreased the survival of beet army-worm eggs. Survival of beet armyworm larvae fed for7 days on leaves treated with neem-based insecticides was reduced to 27, 33, 60, and 61% for neemleaf powder, Ecozin, Agroneem, and Neemix, respectively. Possibilities for adoption of neem-basedinsecticides in commercial cotton for beet armyworm control are discussed.展开更多
基金This research was supported by Natural Resources Canada, Canadian Forest Service. Project No. CFSCB2005-09.
文摘Spruce budworm （Choristoneura fumiferana （Clemens）） is one of the most serious forest insect pests in North America. Laboratory bioassays were performed to determine the lethal doses and lethal time of pyrethrins （a botanical insecticide） on 4th instar larvae of spruce bud-worm using larval dip assay. Results show that the LT50 values（time of 50% larval mortality）for spruce budworm at the pyrethrins concentra-tions of 12.5, 25, 50, 100, and 200 μg·L-1 were 94.78, 45.54, 20.36, 14.39 and 11.37 h, respectively. The percentage of cumulative mortality at the pyrethrins concentrations of 12.5, 25, 50, 100, 200 μg·L-1 was approxi-mately 50%, 67%, 93%, 100% and 100% within 120 h, respectively. The LC50 value （concentration of 50% larval mortality） for the 4th instar lar-vae was 16.1μg·L-1. Thus, larval mortality of spruce budworm increased in a concentration-dependent manner, and lethal time decreased with increasing pyrethin concentrations. These findings suggest that pyrethrins have a potential in controlling spruce budworm populations.
基金Supported by the Special Program for the Construction of Modern Agricultural Industrial Technological System(CARS-30-bc)~~
文摘Apolygus lucorum（Meyer-Dür.） and Erythroneura apicalis（Nawa） are important pests that affect the quality and the yield of grapevine and cause huge economic losses. This paper focuses on the selection of effective botanical pesticides to control A. lucorum and E. apicalis. This experiment explores the effect of several botanical pesticides for A. lucorum and E. apicalis, including the 0.5% veratrine, the0.6% Oxygen·Lactone agent, the 5% natural pyrethrin, the composite neem pesticide, the rotenone and the composite nicotine. The 0.5% veratrine shows a stable control efficacy, which is higher than 60% in Chengdu, while the composite nicotine shows the highest efficacy against A. lucorum, which is above 70%. In Yinchuan,the 0.5% veratrine shows the highest efficacy, against the first generation adults and the second generation larvae of E. apicalis, while the 5% natural pyrethrin shows 100% control efficacy against E. apicalis in Nanjiang. The 0.5% veratrine and the composite neem could be used as effective pesticides to control A. lucorum and the 5% natural pyrethrin can be used to control E. apicalis. They could be widely used in the production of pollution-free grapes.
文摘Three commercial neem [Azadirachta indica A. Juss (Meliaceae)]-basedinsecticides, Agroneem, Ecozin, and Neemix, and a non-commercial neem leaf powder, were evaluatedfor oviposition deterrence, antifeedant effect on larvae, and toxicity to eggs and larvae of thebeet armyworm, Spodoptera exigua (Huebner) (Lepidoptera: Noctuidae), on cotton leaves in thelaboratory. Oviposition deterrence in no-choice, and two- and five-choice assays, was observed forthe neem-based insecticide treatments when compared with a non-treated control. Neem-basedinsecticides also deterred feeding by beet armyworm larvae. Direct contact with neem-basedinsecticides decreased the survival of beet army-worm eggs. Survival of beet armyworm larvae fed for7 days on leaves treated with neem-based insecticides was reduced to 27, 33, 60, and 61% for neemleaf powder, Ecozin, Agroneem, and Neemix, respectively. Possibilities for adoption of neem-basedinsecticides in commercial cotton for beet armyworm control are discussed.
