The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage...The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage thrips. To assess the incidence of spinosad resistance in F. occidentalis field populations in eastern China, survival rates for 24 different populations were compared with those of a susceptible laboratory strain. All populations showed significantly higher resistance to spinosad compared with the control as determined by comparing median lethal concentrations. Two populations from Shouguang and Liaocheng in Shandong Province were classified as having moderate and high levels of resistance to spinosad with a mean resistance ratio of 17.0 and 89.2, respectively. Our research indicates a widespread reduction in spinosad efficacy for controlling F. occidentalis field populations, and that resistance management strategies should be implemented as soon as practicable, to reduce the potential of progressive resistance development and loss of efficacy.展开更多
The effects of glucose and inorganic phosphate on mycelium growth and spinosad production with Saccharopolyspora spinosa were studied. The results showed that the increase of glucose concentration from 18.6g·L^-1...The effects of glucose and inorganic phosphate on mycelium growth and spinosad production with Saccharopolyspora spinosa were studied. The results showed that the increase of glucose concentration from 18.6g·L^-1 to 58.8g·L^-1 could promote the mycelium growth and spinosad production. And when the glucose con- centration increased from 58.8g·L^-1 to 79.6g·L^-1, no obvious change was detected but a slight drop in spinosad production was observed, whereas, when the glucose concentration increased from 79.6g·L^-1 to 115.3g·L^-1, substantial decrease in both mycelium growth and spinosad production occurred. The increase of phosphate concentra- tion from 3.68mmol·L^-1 to 29.41mmol·L^-1 rendered corresponding increase in mycelium growth and spinosad production. When phosphate concentration increased from 29.41mmol·L^-1 to 44.12mmol·L^-1, mycelium growth slightly increased and spinosad production dropped, while when phosphate concentration increased from 44.12mmol·L^-1 to 57.62mmol·L^-1, both mycelium growth and spinosad production decreased sharply. Conclusively, the optimal initial concentration of glucose and phosphate is 58.8g·L^-1 and 29.41mmol·L^-1, respectively. The spinosad fermentation in the production medium containing 58.8g·L^-1 glucose and 29.41mmol·L^-1 phosphate was scaled up in 5-L fermentation and the spinosad production reached 507mg·L^-1, which was 28% higher thar that in the flask fermentation.展开更多
Objective:To investigate the larvicidal and pupicidal activity of spinosad against Anopheles stephensi Listen.Methods:Spinosad from the actinomycete,Saccharopolyspora spinosa was tested against Anopheles stephensi at ...Objective:To investigate the larvicidal and pupicidal activity of spinosad against Anopheles stephensi Listen.Methods:Spinosad from the actinomycete,Saccharopolyspora spinosa was tested against Anopheles stephensi at different concentrations（0.01,0.02,0.04,0.06 and 0.08 ppm.）, and against first to fourth instar larvae and pupae.Results:The larval mortality ranged from 36.1±1.7 in（0.01 ppm） to 79.3±1.8（0.08 ppm） the first instar larva.The LC<sub>50</sub> and LC<sub>90</sub> values of first, second,third and fourth instar larva were 0.001,0.031,0.034,0.036 and 0.0113,0.102,0.111,0.113, respectively.The pupal mortality ranged from 33.0±2.0（0.01 ppm） to 80.0±0.9（0.08 ppm）.The LC<sub>50</sub> and LC<sub>90</sub> values were 0.028 and 0.1020,respectively.The reduction percentage of Anopheles larvae was 82.7%,91.4%and 96.0%after 24,48,72 hours,respectively,while more than 80% reduction was observed after 3 weeks.Conclusions:In the present study spinosad effectively caused mortality of mosquito larvae in both the laboratory and field trial.It is predicted that spinosad is likely to be an effective larvicide for treatment of mosquito breeding sites.展开更多
The diamondback moth, Plutella xylostella L., has developed resistance to most insecticides used for its management. Suggested alternatives to forestall this process include biorational insecticides in mixtures with l...The diamondback moth, Plutella xylostella L., has developed resistance to most insecticides used for its management. Suggested alternatives to forestall this process include biorational insecticides in mixtures with low-risk insecticides. The aim of this study was to select an insecticide or insecticide mixture that could be adopted by small-scale growers for diamondback moth management. The effectiveness of four insecticide mixtures, i.e., Agroneem Plus （neem-derived）, Spinosad （microbial origin）, thiamethoxam （neonicotinoid） and a homemade methanol Jalapefio pepper extract, in laboratory bioassays was evaluated. Binary mixtures were tested against single products at manufacturer＇s label rates. These were applied to collard greens using the leaf dip method and fed to the newly molted 2nd or 3rd instar larvae. Mixtures were evaluated for efficacy based on larval mortality and consumption of leaf discs. The results showed interactions between Jalapefio pepper extract and Spinosad and between the neem-derived Agroneem Plus and thiamethoxam at some of the tested concentrations. Mixtures with at any amount of Spinosad killed all larvae. The neem-based product gave inconsistent results in some treatments; in some case, increased leaf damage did not result in commensurate larval mortalities. The reported resistance of diamondback moth larvae to Spinosad was not observed during this study, neither with Spinosad alone nor in mixtures.展开更多
Cross-resistance, resistance mechanisms, and mode of inheritance of spinosad resistance were studied in the western flower thrip, Frankliniella occidentalis （Pergande）. Spinosad （naturalyte insecticide） showed low...Cross-resistance, resistance mechanisms, and mode of inheritance of spinosad resistance were studied in the western flower thrip, Frankliniella occidentalis （Pergande）. Spinosad （naturalyte insecticide） showed low cross-resistance to prothiophos （organophosphorus insecticide） and chlorphenapyr （respiratory inhibitor） showed some cross-resistance to thiocyclam （nereistoxin）. The synergists PBO （piperonyl butoxide）, DEM （diethyl maleate）, and DEF （s,s,s-tributyl phosphorotrithioate） did not show any synergism on the toxicity of spinosad in the resistant strain （ICS）, indicating that metabolic- mediated detoxification was not responsible for the spinosad resistance, suggesting that spinosad may reduce sensitivity of the target site： the nicotinic acetylcholine receptor and GABA receptor. Following reciprocal crosses, dose-response lines and dominance ratios indicated that spinosad resistance was incompletely dominant and there were no maternal effects. The results of backcross showed that spinosad resistance did not fit a single-gene hypothesis, suggesting that resistance was influenced by several genes.展开更多
To promote spinosad biosynthesis by improving the limited oxygen supply during high-density fermentation of Saccharopolyspora spinosa, the open reading frame of the Vitreoscilla hemoglobin gene was placed under the co...To promote spinosad biosynthesis by improving the limited oxygen supply during high-density fermentation of Saccharopolyspora spinosa, the open reading frame of the Vitreoscilla hemoglobin gene was placed under the control of the promoter for the erythromycin resistance gene by splicing using overlapping extension PCR. This was cloned into the integrating vector pSET152, yielding the Vitreoscilla hemoglobin gene expression plasmid pSET152EVHB. This was then introduced into S. spinosa SP06081 by conjugal transfer, and integrated into the chromosome by site-specific recombination at the integration site ФC31 on pSET152EVHB. The resultant conjugant, S. spinosa S078-1101, was genetically stable. The integration was further confirmed by PCR and Southern blotting analysis. A carbon monoxide differential spectrum assay showed that active Vitreoscilla hemoglobin was successfully expressed in S. spinosa S078-1101. Fermentation results revealed that expression of the Vitreoscilla hemoglobin gene significantly promoted spinosad biosynthesis under normal oxygen and moderately oxygen-limiting conditions （P〈0.01）. These findings demonstrate that integrating expression of the Vitreoscilla hemoglobin gene improves oxygen uptake and is an effective means for the genetic improvement of S. spinosa fermentation. Saccharopolyspora spinosa, spinosad, Vitreoscilla hemoglobin, integrating vector, homologous recombination展开更多
In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects hav...In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored-grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum （Jacquelin duVal）; rusty grain beetle, Cryptolestesferrugineus （Stephens）; lesser grain borer, Rhyzopertha dominica （F.）; sawtoothed grain beetle, Oryzaephilus surinamensis （L.）; rice weevil, Sitophilus oryzae （L.）; maize weevil, Sitophilus zeamais （Motschulsky）; and Indian meal moth, Plodia interpunctella （Htibner）. Corn kernels were treated with spinosad at 0, 0. 1, 0.5, 1, and 2 active ingredient （a.i.） mg/kg for controlling the seven species. Beetle adults or P. interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide-treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad-treated corn, adult mortality of C. ferrugineus, R. dominica, 0. surinamensis, S. oryzae, and S. zeamais was 〉 98% at 1 and 2 mg/kg after 12 days. Spinosad at≥ 0.5 mg/kg completely suppressed egg-to-larval survival after 21 days and egg-to-adult emergence of P. interpunctella after 49 days, whereas 16% T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored-grain insect pests on corn.展开更多
Spinosad is a widely used insecticide that exerts its toxic effect primarily through interactions with the nicotinic acetylcholine receptor. The a6 nicotinic acetyl- choline receptor subunit is involved in spinosad to...Spinosad is a widely used insecticide that exerts its toxic effect primarily through interactions with the nicotinic acetylcholine receptor. The a6 nicotinic acetyl- choline receptor subunit is involved in spinosad toxicity as demonstrated by the high levels of resistance observed in strains lacking a6. RNAi was performed against the Da6 nicotinic acetylcholine receptor subunit in Drosophila melanogaster using the Gal4-UAS system to examine if RNAi would yield results similar to those of a6 null mutants. These Da6-deficient flies were subject to spinosad contact bioassays to evaluate the role of the Da6 nicotinic acetylcholine receptor subunit on spinosad sensitivity. The expression of Da6 was reduced 60%-75% as verified by quantitative polymerase chain reaction. However, there was no change in spinosad sensitivity in D. melanogaster. We repeated RNAi experiments in Tribolium castaneum using injection of dsRNA for Tcasct6. RNAi of Tcasa6 did not result in changes in spinosad sensitivity, similar to results obtained with D. melanogaster. The lack of change in spinosad sensitivity in both D. melanogaster and T. castaneum using two routes of dsRNA administration shows that RNAi may not provide adequate conditions to study the role of nicotinic acetylcholine receptor subunits on insecticide sensitivity due to the inability to completely eliminate expression of the a6 subunit in both species. Potential causes for the lack of change in spinosad sensitivity are discussed.展开更多
基金financially supported by the National Natural Science Foundation of China (31371942)the National Key Research and Development Program,China (2016YFC1200600)the Ministry of Science and Technology,China
文摘The western flower thrips, Frankliniella occidentalis, is one of the most destructive sucking pests of vegetables, fruits and ornamental crops in China. Spinosad is one of the most commonly used insecticides to manage thrips. To assess the incidence of spinosad resistance in F. occidentalis field populations in eastern China, survival rates for 24 different populations were compared with those of a susceptible laboratory strain. All populations showed significantly higher resistance to spinosad compared with the control as determined by comparing median lethal concentrations. Two populations from Shouguang and Liaocheng in Shandong Province were classified as having moderate and high levels of resistance to spinosad with a mean resistance ratio of 17.0 and 89.2, respectively. Our research indicates a widespread reduction in spinosad efficacy for controlling F. occidentalis field populations, and that resistance management strategies should be implemented as soon as practicable, to reduce the potential of progressive resistance development and loss of efficacy.
文摘The effects of glucose and inorganic phosphate on mycelium growth and spinosad production with Saccharopolyspora spinosa were studied. The results showed that the increase of glucose concentration from 18.6g·L^-1 to 58.8g·L^-1 could promote the mycelium growth and spinosad production. And when the glucose con- centration increased from 58.8g·L^-1 to 79.6g·L^-1, no obvious change was detected but a slight drop in spinosad production was observed, whereas, when the glucose concentration increased from 79.6g·L^-1 to 115.3g·L^-1, substantial decrease in both mycelium growth and spinosad production occurred. The increase of phosphate concentra- tion from 3.68mmol·L^-1 to 29.41mmol·L^-1 rendered corresponding increase in mycelium growth and spinosad production. When phosphate concentration increased from 29.41mmol·L^-1 to 44.12mmol·L^-1, mycelium growth slightly increased and spinosad production dropped, while when phosphate concentration increased from 44.12mmol·L^-1 to 57.62mmol·L^-1, both mycelium growth and spinosad production decreased sharply. Conclusively, the optimal initial concentration of glucose and phosphate is 58.8g·L^-1 and 29.41mmol·L^-1, respectively. The spinosad fermentation in the production medium containing 58.8g·L^-1 glucose and 29.41mmol·L^-1 phosphate was scaled up in 5-L fermentation and the spinosad production reached 507mg·L^-1, which was 28% higher thar that in the flask fermentation.
文摘Objective:To investigate the larvicidal and pupicidal activity of spinosad against Anopheles stephensi Listen.Methods:Spinosad from the actinomycete,Saccharopolyspora spinosa was tested against Anopheles stephensi at different concentrations（0.01,0.02,0.04,0.06 and 0.08 ppm.）, and against first to fourth instar larvae and pupae.Results:The larval mortality ranged from 36.1±1.7 in（0.01 ppm） to 79.3±1.8（0.08 ppm） the first instar larva.The LC<sub>50</sub> and LC<sub>90</sub> values of first, second,third and fourth instar larva were 0.001,0.031,0.034,0.036 and 0.0113,0.102,0.111,0.113, respectively.The pupal mortality ranged from 33.0±2.0（0.01 ppm） to 80.0±0.9（0.08 ppm）.The LC<sub>50</sub> and LC<sub>90</sub> values were 0.028 and 0.1020,respectively.The reduction percentage of Anopheles larvae was 82.7%,91.4%and 96.0%after 24,48,72 hours,respectively,while more than 80% reduction was observed after 3 weeks.Conclusions:In the present study spinosad effectively caused mortality of mosquito larvae in both the laboratory and field trial.It is predicted that spinosad is likely to be an effective larvicide for treatment of mosquito breeding sites.
文摘The diamondback moth, Plutella xylostella L., has developed resistance to most insecticides used for its management. Suggested alternatives to forestall this process include biorational insecticides in mixtures with low-risk insecticides. The aim of this study was to select an insecticide or insecticide mixture that could be adopted by small-scale growers for diamondback moth management. The effectiveness of four insecticide mixtures, i.e., Agroneem Plus （neem-derived）, Spinosad （microbial origin）, thiamethoxam （neonicotinoid） and a homemade methanol Jalapefio pepper extract, in laboratory bioassays was evaluated. Binary mixtures were tested against single products at manufacturer＇s label rates. These were applied to collard greens using the leaf dip method and fed to the newly molted 2nd or 3rd instar larvae. Mixtures were evaluated for efficacy based on larval mortality and consumption of leaf discs. The results showed interactions between Jalapefio pepper extract and Spinosad and between the neem-derived Agroneem Plus and thiamethoxam at some of the tested concentrations. Mixtures with at any amount of Spinosad killed all larvae. The neem-based product gave inconsistent results in some treatments; in some case, increased leaf damage did not result in commensurate larval mortalities. The reported resistance of diamondback moth larvae to Spinosad was not observed during this study, neither with Spinosad alone nor in mixtures.
文摘Cross-resistance, resistance mechanisms, and mode of inheritance of spinosad resistance were studied in the western flower thrip, Frankliniella occidentalis （Pergande）. Spinosad （naturalyte insecticide） showed low cross-resistance to prothiophos （organophosphorus insecticide） and chlorphenapyr （respiratory inhibitor） showed some cross-resistance to thiocyclam （nereistoxin）. The synergists PBO （piperonyl butoxide）, DEM （diethyl maleate）, and DEF （s,s,s-tributyl phosphorotrithioate） did not show any synergism on the toxicity of spinosad in the resistant strain （ICS）, indicating that metabolic- mediated detoxification was not responsible for the spinosad resistance, suggesting that spinosad may reduce sensitivity of the target site： the nicotinic acetylcholine receptor and GABA receptor. Following reciprocal crosses, dose-response lines and dominance ratios indicated that spinosad resistance was incompletely dominant and there were no maternal effects. The results of backcross showed that spinosad resistance did not fit a single-gene hypothesis, suggesting that resistance was influenced by several genes.
基金supported by the National Basic Research Program of China (Grant Nos. 2012CB722301 and 2011CB111605)the National High Technology Research and Development Project of China (Grant No. 2011AA10A203)the National Natural Science Foundation of China (Grant No. 31070006)
文摘To promote spinosad biosynthesis by improving the limited oxygen supply during high-density fermentation of Saccharopolyspora spinosa, the open reading frame of the Vitreoscilla hemoglobin gene was placed under the control of the promoter for the erythromycin resistance gene by splicing using overlapping extension PCR. This was cloned into the integrating vector pSET152, yielding the Vitreoscilla hemoglobin gene expression plasmid pSET152EVHB. This was then introduced into S. spinosa SP06081 by conjugal transfer, and integrated into the chromosome by site-specific recombination at the integration site ФC31 on pSET152EVHB. The resultant conjugant, S. spinosa S078-1101, was genetically stable. The integration was further confirmed by PCR and Southern blotting analysis. A carbon monoxide differential spectrum assay showed that active Vitreoscilla hemoglobin was successfully expressed in S. spinosa S078-1101. Fermentation results revealed that expression of the Vitreoscilla hemoglobin gene significantly promoted spinosad biosynthesis under normal oxygen and moderately oxygen-limiting conditions （P〈0.01）. These findings demonstrate that integrating expression of the Vitreoscilla hemoglobin gene improves oxygen uptake and is an effective means for the genetic improvement of S. spinosa fermentation. Saccharopolyspora spinosa, spinosad, Vitreoscilla hemoglobin, integrating vector, homologous recombination
文摘In January 2005, the United States Environmental Protection Agency registered spinosad as a stored grain protectant. No referenced data on the efficacy of spinosad on corn in suppressing major stored-grain insects have been published. In this paper, we evaluated the efficacy of spinosad against seven major stored-grain insects on shelled corn in the laboratory. Insect species tested were the red flour beetle, Tribolium castaneum （Jacquelin duVal）; rusty grain beetle, Cryptolestesferrugineus （Stephens）; lesser grain borer, Rhyzopertha dominica （F.）; sawtoothed grain beetle, Oryzaephilus surinamensis （L.）; rice weevil, Sitophilus oryzae （L.）; maize weevil, Sitophilus zeamais （Motschulsky）; and Indian meal moth, Plodia interpunctella （Htibner）. Corn kernels were treated with spinosad at 0, 0. 1, 0.5, 1, and 2 active ingredient （a.i.） mg/kg for controlling the seven species. Beetle adults or P. interpunctella eggs were introduced into each container holding 100 g of untreated or insecticide-treated corn. The seven insect species survived well on the control treatment, produced 28 to 336 progeny, and caused significant kernel damage after 49 days. On spinosad-treated corn, adult mortality of C. ferrugineus, R. dominica, 0. surinamensis, S. oryzae, and S. zeamais was 〉 98% at 1 and 2 mg/kg after 12 days. Spinosad at≥ 0.5 mg/kg completely suppressed egg-to-larval survival after 21 days and egg-to-adult emergence of P. interpunctella after 49 days, whereas 16% T. castaneum adults survived at 1 mg/kg after 12 days. Spinosad at 1 or 2 mg/kg provided complete or near complete suppression of progeny production and kernel damage of all species after 49 days. Our results indicate that spinosad at the current labeled rate of 1 mg/kg is effective against the seven stored-grain insect pests on corn.
文摘Spinosad is a widely used insecticide that exerts its toxic effect primarily through interactions with the nicotinic acetylcholine receptor. The a6 nicotinic acetyl- choline receptor subunit is involved in spinosad toxicity as demonstrated by the high levels of resistance observed in strains lacking a6. RNAi was performed against the Da6 nicotinic acetylcholine receptor subunit in Drosophila melanogaster using the Gal4-UAS system to examine if RNAi would yield results similar to those of a6 null mutants. These Da6-deficient flies were subject to spinosad contact bioassays to evaluate the role of the Da6 nicotinic acetylcholine receptor subunit on spinosad sensitivity. The expression of Da6 was reduced 60%-75% as verified by quantitative polymerase chain reaction. However, there was no change in spinosad sensitivity in D. melanogaster. We repeated RNAi experiments in Tribolium castaneum using injection of dsRNA for Tcasct6. RNAi of Tcasa6 did not result in changes in spinosad sensitivity, similar to results obtained with D. melanogaster. The lack of change in spinosad sensitivity in both D. melanogaster and T. castaneum using two routes of dsRNA administration shows that RNAi may not provide adequate conditions to study the role of nicotinic acetylcholine receptor subunits on insecticide sensitivity due to the inability to completely eliminate expression of the a6 subunit in both species. Potential causes for the lack of change in spinosad sensitivity are discussed.
