[Objective]The paper was to understand the population development regularity of Gastrolina depressa in natural environment in Guizhou Province.[Method]The population dynamics of G.depressa was studied by establishing ...[Objective]The paper was to understand the population development regularity of Gastrolina depressa in natural environment in Guizhou Province.[Method]The population dynamics of G.depressa was studied by establishing life table of natural population of G.depressa via field observation and calculating dynamic trend index of population.[Result]The mortality rates in egg stage,pupal stage and adult stage accounted for 26.42%,10.96%and 8.22%of the total mortality rate,respectively.The mortality rate in larval stage was the highest,accounting for 54.40%of the total mortality rate,higher than the total mortality rate in the other three stages.The population dynamic trend index I=9.25,I>1 indicated that the population showed an upward trend.[Conclusion]Under the natural conditions,the population of G.depressa shows upward trend,and human intervention is needed to control the population.The larval stage is the weak stage of the insect,which is the best time to control the insect.展开更多
The fall armyworm(FAW),Spodoptera frugiperda Smith(Lepidoptera:Noctuidae)is an important agricultural pest that invaded China in the middle of December 2018.As a polyphagous pest,FAW is identified as a serious threat ...The fall armyworm(FAW),Spodoptera frugiperda Smith(Lepidoptera:Noctuidae)is an important agricultural pest that invaded China in the middle of December 2018.As a polyphagous pest,FAW is identified as a serious threat to agricultural production and food security in China.Pepper(Capsicum annuum L.),tomato(Solanum lycopersicum Mill.)and eggplant(Solanum melongena L.)are three of dominant solanaceous vegetables of this country.To our knowledge,the effects of these plants on the performances of FAW have not been well studied.In this study we assessed the fitness of this pest to these three plants.Results showed that FAW can complete its life cycle when fed with tomato and pepper,but not on eggplant.The population parameters of FAW fed with maize(Zea mays L.)and the three solanaceous vegetables were compared using the age-stage,two-sex life table method.Developmental duration was significantly different in the larval stage,but not in the pupae stage.FAW fed with pepper had the longest pre-adult period(41.73 d)and the lightest pupal weight(0.1134 g);the survival rate was lower than FAW fed with tomato.Significant differences were observed in the mean fecundity of female,with the highest(943.95 eggs)laid by FAW fed with tomato.FAW had the shortest mean generation time(T),the highest intrinsic rate of increase(r)and finite rate of increase(λ)on maize,and the highest net reproductive rate(R_(0))on tomato.Overall,FAW fitness on the three solanaceous vegetables was:tomato>pepper>eggplant.This study provides the foundation for further assessment of FAW risk to solanaceous vegetables and for establishing corresponding control strategies in China.展开更多
Life expectancy of the elderly is a significant problem in China, and it changes not only the health care, but also the pension. This study used tracking data from the Chinese Urban and Rural Elderly Population Survey...Life expectancy of the elderly is a significant problem in China, and it changes not only the health care, but also the pension. This study used tracking data from the Chinese Urban and Rural Elderly Population Survey to calculate the age-specific Active Life Expectancy (ALE) of the Chinese elderly population aged 60 years and over. For analysis, this population was divided into different sub-populations according to gender, census register and region. The main conclusions of our study are as follows: 1) The quality of life for elderly males may be greater than that for elderly females;2) There were significant differences in Active Life Expectancy (ALE) and Inactive Life Expectancy (ILE) between urban and rural elderly;3) The differences in ALE between the eastern, central and western regions of China were not significant;and 4) The increased remaining life expectancy of the elderly was mainly attributed to the extended ALE in the lower age group and the expanded ILE in the higher age group. This study expands the knowledge of Chinese elderly’s life expectancy in different health status.展开更多
This study identifies China’s mortality pattern families by using data from national and provincial censuses and one-percent sample surveys of China,and then compares them with families in the Coale-Demeny and United...This study identifies China’s mortality pattern families by using data from national and provincial censuses and one-percent sample surveys of China,and then compares them with families in the Coale-Demeny and United Nations model life tables.Based on available data,the findings show there are seven families of mortality patterns in China.Their characteristics differ primarily during adolescence,and young and middle adulthood while resembling during infancy,toddlerhood,childhood and late adulthood or old age.Abnormally higher mortality is seen in females than males during infancy and childhood in three of the seven families of mortality patterns.As for the difference in male and female mortality in old age in the seven families of mortality patterns,it can be ignored.The comparison with the Coale-Demeny and UN model life tables shows the deviations of China’s families of mortality patterns from the families in the two model life tables vary at different mortality levels,with some similarities existing in the deviations at high and low mortality levels,whereas the difference in the deviations at the medium mortality level primarily appears during non-elderly years.The widely used Coale-Demeny West Pattern and the United Nations General Pattern,however,are not applicable to the studies of China’s mortality.Miscalculations commonly happen in the mortality patterns for adolescents,young and middle adults,and elderly people.展开更多
Diglyphus wani(Hymenoptera:Eulophidae)is a dominant parasitoid that attacks agromyzid leafminers.Two reproductive types occur in D.wani:arrhenotoky(in which virgin females produce only male offspring;and virgin female...Diglyphus wani(Hymenoptera:Eulophidae)is a dominant parasitoid that attacks agromyzid leafminers.Two reproductive types occur in D.wani:arrhenotoky(in which virgin females produce only male offspring;and virgin females mate with males to produce bisexual offspring)and thelytoky(in which virgin females produce female offspring).As a potential biological control agent,exploring the differences in the relevant biological parameters of both strains is necessary.In this study,comparisons between the two strains of D.wani were performed by evaluating the life table and host-killing rate.The thelytokous strain exhibited significantly better life table parameters than its arrhenotokous counterpart.Higher values for the intrinsic rate of increase,finite rate of increase,net reproductive rate,and fecundity were found in the thelytokous strain.The thelytokous strain also performed better than the arrhenotokous strain in terms of net parasitism,host-feeding,host-stinging,and total host-killing rates.Thus,populations of the thelytokous strain could grow fast and kill more hosts.In conclusion,the thelytokous strain of D.wani may be the more promising biological agent against agromyzid leafminers compared to its arrhenotokous counterpart.Also,since the thelytokous strain of D.wani is only known to produce females,it should be given priority in future biocontrol applications owing to the cost savings of breeding only females.展开更多
The use of artificial diets to mass reared insect stock under laboratory conditions, promotes knowledge about the biology, behavior, and nutritional requirements of insects;with such information being fundamental for ...The use of artificial diets to mass reared insect stock under laboratory conditions, promotes knowledge about the biology, behavior, and nutritional requirements of insects;with such information being fundamental for the formulation of efficient integrated pest management programs (IPM) strategies. However, the artificial diets used for rearing Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in the laboratory in this study, do not contain wheat germ, used for routine laboratory rearing. The aim of this study was to compare food preference and consumption by S. frugiperda larvae, as well as evaluate insect developmental parameters in the standard diet and the bean-based diets under laboratory conditions. Four artificial diets were used: a standard diet based on broad beans (Phaseolus vulgaris L.) used to rear S. frugiperda (D1), a diet with the substitution of two types of beans, cowpea (Vigna unguiculata L.) (D2) and pigeon pea (Cajanus cajan L) (D3);and a diet of fresh corn leaves (D4), the host plant of the pest species. Using a multiple-choice test, we observed that the larvae preferred diets D4 followed by D1. The relative consumption rate (RCR), relative growth rate (RGR), relative metabolic rate (RMR), approximate digestibility (AD), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and the metabolic cost (CM) for S. frugiperda fifth instar larvae varied among diets. The diet D4 resulted in better ingestion, digestion, assimilation, and conversion of food, but with a metabolic cost to assimilate the food. The different bean varieties present in the diet influenced larval length, larval periods, larval survival, pupal periods, sex ratio, pupal weight, and pupal survival;but fecundity and longevity of adults were not affected. The different bean-based diets did positively influence population growth, with the most outstanding being D4. From the results of this study, the most adequate diet for rearing S. frugiperda in the laboratory is D4.展开更多
Agasicles hygrophila has been introduced worldwide as a control agent for the invasive weed Alternanthera philoxeroides.However,global warming has potential impact on its controlling efficacy.The aim of this research ...Agasicles hygrophila has been introduced worldwide as a control agent for the invasive weed Alternanthera philoxeroides.However,global warming has potential impact on its controlling efficacy.The aim of this research was to explore the primary factors responsible for the greatly reduced A.hygrophila population in hot summers.To imitate the temperature conditions in summers,different developmental stages of hygrophila were treated with high temperatures from 32.5℃ to 45℃ for 1-5 h.Based on the survival rate,the heat tolerance of each developmental stage was ranked from lowest to highest as follows:egg,1st,2nd,3rd instar larva,adult and pupa.Eggs showed the lowest heat tolerance with 37.5℃ as the critical temperature affecting larval hatching.Heat treatment of the A.hygrophila eggs at 37.5℃ for 1 h decreased the hatch rate to 24%.Our results indicated that when compared with the control at 25℃,1 h treatment at 37.5℃ prolonged the duration of the egg stage,shortened the duration of oviposition and total longevity,and changed the reproductive pattern of A.hygrophila.The net reproductive rate,intrinsic rate and finite rate were all significantly reduced.The results suggest that low heat tolerance of the eggs was the major factor responsible for the reduction of A.hygrophila populations,and the key temperature was 37.5°C.Therefore,appropriate measures should be taken to protect eggs in order to maintain the efficacy of A.hygrophila in the biological control of A.philoxeroides in hot summers.展开更多
The effects of temperature on population characteristics of Artemia parthenogenetica Gahai from the Gahai Salt Lake,Qinghai Province,China,were studied in the laboratory at a salinity of 60‰.The major conclusions are...The effects of temperature on population characteristics of Artemia parthenogenetica Gahai from the Gahai Salt Lake,Qinghai Province,China,were studied in the laboratory at a salinity of 60‰.The major conclusions are as follows:(1)It was found that the adaptive temperature for the development of brine shrimp ranged from 10℃to 39℃.The threshold temperature of development(TD)and the effective accumulative temperature(TA)for hatching were 9.94℃·d and(22.912.08)℃·d,respectively.The TD and TA for the larva were 10.33℃·d and(261.2624.1)℃·d,respectively,and for the whole generation were 10.28℃and(458.6857.60)℃·d,respectively.(2)It showed that the population’s net reproduction rate(R_(o)),the intrinsic rate of natural increase(r_(m)),the mean generation time(T),the finite rate of increase(λ),and the days for population to double(t)of the brine shrimp were determined over temperatures ranging from 19℃to 34℃by analyzing the life table and numerical model.In the temperature range of 14.3℃to 37.3℃for R_(o)>1,the optimum temperature(℃)for R_(o),rm,λ,and t were 25.8℃,29.8℃,30.5℃,and 29.02℃,respectively.The maximum values of R_(o),r_(m) andλwere 54.86 ind.,0.106138/d,and 1.1070/d,respectively.The minimum value of t was 4.73 d.The value of T was in a range of 96.77 to 16.10 d.(3)Based on the 1993-1994 and 1997 data of the water temperature in the Gahai Salt Lake,Qinghai Province,it was estimated that the number of generation of A.parthenogenetica Gahai and the number of the reproductive peak value were 2.670.34 and 4.690.43 in a year,respectively.The peak of nauplii of the first generation was on April 20 to 28.The last whole generation began on August 10.The first reproductive peak was on June 18 to 25.The last reproductive peak was on September 12 to 17.The nauplii that hatched after September 1 cannot complete the development from nauplii to adults because of insufficient habitat effective accumulative temperature.During the period from July 11 to September 20,there was a relatively high productivity of the population.In this case,doubling the population would take less than 30 d,and the intrinsic rate of natural increase was over 0.02/d.Therefore,the value of resource exploitation would be maximal during that period annually.展开更多
基金Supported by Basic Research Program of Guizhou Department of Science and Technology(QKHJC[2017]1099).
文摘[Objective]The paper was to understand the population development regularity of Gastrolina depressa in natural environment in Guizhou Province.[Method]The population dynamics of G.depressa was studied by establishing life table of natural population of G.depressa via field observation and calculating dynamic trend index of population.[Result]The mortality rates in egg stage,pupal stage and adult stage accounted for 26.42%,10.96%and 8.22%of the total mortality rate,respectively.The mortality rate in larval stage was the highest,accounting for 54.40%of the total mortality rate,higher than the total mortality rate in the other three stages.The population dynamic trend index I=9.25,I>1 indicated that the population showed an upward trend.[Conclusion]Under the natural conditions,the population of G.depressa shows upward trend,and human intervention is needed to control the population.The larval stage is the weak stage of the insect,which is the best time to control the insect.
基金supported by the Science and Technology Program of Guizhou Province,China([2019]2412)the Basic Research Program(Science and Technology)of Guizhou Province,China([2020]1Z021)。
文摘The fall armyworm(FAW),Spodoptera frugiperda Smith(Lepidoptera:Noctuidae)is an important agricultural pest that invaded China in the middle of December 2018.As a polyphagous pest,FAW is identified as a serious threat to agricultural production and food security in China.Pepper(Capsicum annuum L.),tomato(Solanum lycopersicum Mill.)and eggplant(Solanum melongena L.)are three of dominant solanaceous vegetables of this country.To our knowledge,the effects of these plants on the performances of FAW have not been well studied.In this study we assessed the fitness of this pest to these three plants.Results showed that FAW can complete its life cycle when fed with tomato and pepper,but not on eggplant.The population parameters of FAW fed with maize(Zea mays L.)and the three solanaceous vegetables were compared using the age-stage,two-sex life table method.Developmental duration was significantly different in the larval stage,but not in the pupae stage.FAW fed with pepper had the longest pre-adult period(41.73 d)and the lightest pupal weight(0.1134 g);the survival rate was lower than FAW fed with tomato.Significant differences were observed in the mean fecundity of female,with the highest(943.95 eggs)laid by FAW fed with tomato.FAW had the shortest mean generation time(T),the highest intrinsic rate of increase(r)and finite rate of increase(λ)on maize,and the highest net reproductive rate(R_(0))on tomato.Overall,FAW fitness on the three solanaceous vegetables was:tomato>pepper>eggplant.This study provides the foundation for further assessment of FAW risk to solanaceous vegetables and for establishing corresponding control strategies in China.
文摘Life expectancy of the elderly is a significant problem in China, and it changes not only the health care, but also the pension. This study used tracking data from the Chinese Urban and Rural Elderly Population Survey to calculate the age-specific Active Life Expectancy (ALE) of the Chinese elderly population aged 60 years and over. For analysis, this population was divided into different sub-populations according to gender, census register and region. The main conclusions of our study are as follows: 1) The quality of life for elderly males may be greater than that for elderly females;2) There were significant differences in Active Life Expectancy (ALE) and Inactive Life Expectancy (ILE) between urban and rural elderly;3) The differences in ALE between the eastern, central and western regions of China were not significant;and 4) The increased remaining life expectancy of the elderly was mainly attributed to the extended ALE in the lower age group and the expanded ILE in the higher age group. This study expands the knowledge of Chinese elderly’s life expectancy in different health status.
基金supported by the 7th National Population Census Key Research granted by National Bureau of Statistics of China(grant number RKPCZB16).
文摘This study identifies China’s mortality pattern families by using data from national and provincial censuses and one-percent sample surveys of China,and then compares them with families in the Coale-Demeny and United Nations model life tables.Based on available data,the findings show there are seven families of mortality patterns in China.Their characteristics differ primarily during adolescence,and young and middle adulthood while resembling during infancy,toddlerhood,childhood and late adulthood or old age.Abnormally higher mortality is seen in females than males during infancy and childhood in three of the seven families of mortality patterns.As for the difference in male and female mortality in old age in the seven families of mortality patterns,it can be ignored.The comparison with the Coale-Demeny and UN model life tables shows the deviations of China’s families of mortality patterns from the families in the two model life tables vary at different mortality levels,with some similarities existing in the deviations at high and low mortality levels,whereas the difference in the deviations at the medium mortality level primarily appears during non-elderly years.The widely used Coale-Demeny West Pattern and the United Nations General Pattern,however,are not applicable to the studies of China’s mortality.Miscalculations commonly happen in the mortality patterns for adolescents,young and middle adults,and elderly people.
基金This study was supported by the National Natural Science Foundation of China(31972344 and 31772236)the National Key R&D Program of China(2021YFC2600400)the Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(caascx2022-2025-IAS).
文摘Diglyphus wani(Hymenoptera:Eulophidae)is a dominant parasitoid that attacks agromyzid leafminers.Two reproductive types occur in D.wani:arrhenotoky(in which virgin females produce only male offspring;and virgin females mate with males to produce bisexual offspring)and thelytoky(in which virgin females produce female offspring).As a potential biological control agent,exploring the differences in the relevant biological parameters of both strains is necessary.In this study,comparisons between the two strains of D.wani were performed by evaluating the life table and host-killing rate.The thelytokous strain exhibited significantly better life table parameters than its arrhenotokous counterpart.Higher values for the intrinsic rate of increase,finite rate of increase,net reproductive rate,and fecundity were found in the thelytokous strain.The thelytokous strain also performed better than the arrhenotokous strain in terms of net parasitism,host-feeding,host-stinging,and total host-killing rates.Thus,populations of the thelytokous strain could grow fast and kill more hosts.In conclusion,the thelytokous strain of D.wani may be the more promising biological agent against agromyzid leafminers compared to its arrhenotokous counterpart.Also,since the thelytokous strain of D.wani is only known to produce females,it should be given priority in future biocontrol applications owing to the cost savings of breeding only females.
文摘The use of artificial diets to mass reared insect stock under laboratory conditions, promotes knowledge about the biology, behavior, and nutritional requirements of insects;with such information being fundamental for the formulation of efficient integrated pest management programs (IPM) strategies. However, the artificial diets used for rearing Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in the laboratory in this study, do not contain wheat germ, used for routine laboratory rearing. The aim of this study was to compare food preference and consumption by S. frugiperda larvae, as well as evaluate insect developmental parameters in the standard diet and the bean-based diets under laboratory conditions. Four artificial diets were used: a standard diet based on broad beans (Phaseolus vulgaris L.) used to rear S. frugiperda (D1), a diet with the substitution of two types of beans, cowpea (Vigna unguiculata L.) (D2) and pigeon pea (Cajanus cajan L) (D3);and a diet of fresh corn leaves (D4), the host plant of the pest species. Using a multiple-choice test, we observed that the larvae preferred diets D4 followed by D1. The relative consumption rate (RCR), relative growth rate (RGR), relative metabolic rate (RMR), approximate digestibility (AD), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), and the metabolic cost (CM) for S. frugiperda fifth instar larvae varied among diets. The diet D4 resulted in better ingestion, digestion, assimilation, and conversion of food, but with a metabolic cost to assimilate the food. The different bean varieties present in the diet influenced larval length, larval periods, larval survival, pupal periods, sex ratio, pupal weight, and pupal survival;but fecundity and longevity of adults were not affected. The different bean-based diets did positively influence population growth, with the most outstanding being D4. From the results of this study, the most adequate diet for rearing S. frugiperda in the laboratory is D4.
文摘Agasicles hygrophila has been introduced worldwide as a control agent for the invasive weed Alternanthera philoxeroides.However,global warming has potential impact on its controlling efficacy.The aim of this research was to explore the primary factors responsible for the greatly reduced A.hygrophila population in hot summers.To imitate the temperature conditions in summers,different developmental stages of hygrophila were treated with high temperatures from 32.5℃ to 45℃ for 1-5 h.Based on the survival rate,the heat tolerance of each developmental stage was ranked from lowest to highest as follows:egg,1st,2nd,3rd instar larva,adult and pupa.Eggs showed the lowest heat tolerance with 37.5℃ as the critical temperature affecting larval hatching.Heat treatment of the A.hygrophila eggs at 37.5℃ for 1 h decreased the hatch rate to 24%.Our results indicated that when compared with the control at 25℃,1 h treatment at 37.5℃ prolonged the duration of the egg stage,shortened the duration of oviposition and total longevity,and changed the reproductive pattern of A.hygrophila.The net reproductive rate,intrinsic rate and finite rate were all significantly reduced.The results suggest that low heat tolerance of the eggs was the major factor responsible for the reduction of A.hygrophila populations,and the key temperature was 37.5°C.Therefore,appropriate measures should be taken to protect eggs in order to maintain the efficacy of A.hygrophila in the biological control of A.philoxeroides in hot summers.
基金sponsored by the National Natural Science Foundation of China(Grant Nos.40573056 and 40531002)the Foundation of Open Laboratory of Saline Lakes Resources&Environment of The Ministry of Land and Resources PRC(No.KL05-10).
文摘The effects of temperature on population characteristics of Artemia parthenogenetica Gahai from the Gahai Salt Lake,Qinghai Province,China,were studied in the laboratory at a salinity of 60‰.The major conclusions are as follows:(1)It was found that the adaptive temperature for the development of brine shrimp ranged from 10℃to 39℃.The threshold temperature of development(TD)and the effective accumulative temperature(TA)for hatching were 9.94℃·d and(22.912.08)℃·d,respectively.The TD and TA for the larva were 10.33℃·d and(261.2624.1)℃·d,respectively,and for the whole generation were 10.28℃and(458.6857.60)℃·d,respectively.(2)It showed that the population’s net reproduction rate(R_(o)),the intrinsic rate of natural increase(r_(m)),the mean generation time(T),the finite rate of increase(λ),and the days for population to double(t)of the brine shrimp were determined over temperatures ranging from 19℃to 34℃by analyzing the life table and numerical model.In the temperature range of 14.3℃to 37.3℃for R_(o)>1,the optimum temperature(℃)for R_(o),rm,λ,and t were 25.8℃,29.8℃,30.5℃,and 29.02℃,respectively.The maximum values of R_(o),r_(m) andλwere 54.86 ind.,0.106138/d,and 1.1070/d,respectively.The minimum value of t was 4.73 d.The value of T was in a range of 96.77 to 16.10 d.(3)Based on the 1993-1994 and 1997 data of the water temperature in the Gahai Salt Lake,Qinghai Province,it was estimated that the number of generation of A.parthenogenetica Gahai and the number of the reproductive peak value were 2.670.34 and 4.690.43 in a year,respectively.The peak of nauplii of the first generation was on April 20 to 28.The last whole generation began on August 10.The first reproductive peak was on June 18 to 25.The last reproductive peak was on September 12 to 17.The nauplii that hatched after September 1 cannot complete the development from nauplii to adults because of insufficient habitat effective accumulative temperature.During the period from July 11 to September 20,there was a relatively high productivity of the population.In this case,doubling the population would take less than 30 d,and the intrinsic rate of natural increase was over 0.02/d.Therefore,the value of resource exploitation would be maximal during that period annually.
