Parasitoids are key regulators in ecological communities and widely used as agents in biocontrol programmes.The fall armyworm,Spodoptera frugiperda,recently invaded multiple continents and caused substantial economic ...Parasitoids are key regulators in ecological communities and widely used as agents in biocontrol programmes.The fall armyworm,Spodoptera frugiperda,recently invaded multiple continents and caused substantial economic losses in agriculture.Pyemotes zhonghuajia,a newly identified mite parasitoid,has shown potential for controlling various agricultural insect pests.Therefore,this study tested the performance of P.zhonghuajia in parasitising S.frugiperda.We also investigated the sublethal effects of parasitism by P.zhonghuajia on host fitness traits,transgenerational impacts,and cellular and humoral immunity.Our result showed that the fifth-instar larvae of S.frugiperda parasitised by 40 P.zhonghuajia were all dead(i.e.,a lethal effect),while parasitism by 5 or 10 P.zhonghuajia was considered sublethal since many S.frugiperda survived to adulthood and produced offspring after mating.The sublethal influences from parasitism by P.zhonghuajia resulted in reduced pupal weight,adult emergence rate and fecundity,but increased developmental time and longevity.Parasitism at both lethal(40 mites)and sublethal(10 mites)levels impaired the cellular and humoral immunity of S.frugiperda.This study presents the first empirical evidence that mite parasitoids can negatively influence host immunity.Moreover,it provides insights into the biocontrol potential of mite parasitoids and their interactions with hosts.展开更多
Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua...Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua exposed to cadmium and its effects on the growth and development of the parents and the offspring were investigated.Under the stress of different concentrations of cadmium(0.2,3.2,and 51.2 mg kg^(-1)),the cadmium content in each tissue of S.exigua increased in a dose-dependent manner.At the larval stage,the highest cadmium accumulation was found in midgut in all three cadmium treatments,but at the adult stage,the highest cadmium content was found in fat body.In addition,the cadmium content in ovaries was much higher than in testes.When F1S.exigua was stressed by cadmium and the F_(2)generation was not fed a cadmium-containing diet,the larval survival,pupation rate,emergence rate and fecundity of the F_(2)generation were significantly reduced in the 51.2 mg kg^(-1)treatment compared to the corresponding F1generation.Even in the F_(2)generation of the 3.2 mg kg^(-1)treatment,the fecundity was significantly lower than in the parental generation.The fecundity of the only-female stressed treatment was significantly lower than that of the only-male stressed treatment at the 3.2 and 51.2 mg kg^(-1)cadmium exposure levels.When only mothers were stressed at the larval stage,the fecundity of the F_(2)generation was significantly lower than that of the F1generation in the 51.2 mg kg^(-1)treatment,and it was also significantly lower than in the 3.2 and 0.2 mg kg^(-1)treatments.The results of our study can provide useful information for forecasting the population increase trends under different heavy metal stress conditions and for the reliable environmental risk assessment of heavy metal pollution.展开更多
基金funded by the National Natural Science Foundation of China(32060637 and 32260708)the Highlevel Talent Innovation and Entrepreneurship Funding Project in Guizhou Province,China((2021)01)+3 种基金the Guizhou Provincial Science and Technology Innovation Talent Team Project,China(Qian Ke He Pingtai RencaiCXTD(2021)004)the Systematic and Applied Acarology Society International Joint Project,England(2022(01))the Growth Project of Youth Talent in Ordinary Universities in Guizhou Province,China((2021)079)the Natural Science Special Project in Guizhou University,China((2020)02)。
文摘Parasitoids are key regulators in ecological communities and widely used as agents in biocontrol programmes.The fall armyworm,Spodoptera frugiperda,recently invaded multiple continents and caused substantial economic losses in agriculture.Pyemotes zhonghuajia,a newly identified mite parasitoid,has shown potential for controlling various agricultural insect pests.Therefore,this study tested the performance of P.zhonghuajia in parasitising S.frugiperda.We also investigated the sublethal effects of parasitism by P.zhonghuajia on host fitness traits,transgenerational impacts,and cellular and humoral immunity.Our result showed that the fifth-instar larvae of S.frugiperda parasitised by 40 P.zhonghuajia were all dead(i.e.,a lethal effect),while parasitism by 5 or 10 P.zhonghuajia was considered sublethal since many S.frugiperda survived to adulthood and produced offspring after mating.The sublethal influences from parasitism by P.zhonghuajia resulted in reduced pupal weight,adult emergence rate and fecundity,but increased developmental time and longevity.Parasitism at both lethal(40 mites)and sublethal(10 mites)levels impaired the cellular and humoral immunity of S.frugiperda.This study presents the first empirical evidence that mite parasitoids can negatively influence host immunity.Moreover,it provides insights into the biocontrol potential of mite parasitoids and their interactions with hosts.
基金partially supported by the Open Project Program from the Key Laboratory of South Subtropical Fruit Biology and Genetic Resource Utilization(Ministry of Agriculture and Rural Affairs),China(212103)。
文摘Vegetable fields are often contaminated by heavy metals,and Spodoptera exigua is a major vegetable pest which is stressed by heavy metals mainly by feeding.In this study,cadmium accumulation in the tissues of S.exigua exposed to cadmium and its effects on the growth and development of the parents and the offspring were investigated.Under the stress of different concentrations of cadmium(0.2,3.2,and 51.2 mg kg^(-1)),the cadmium content in each tissue of S.exigua increased in a dose-dependent manner.At the larval stage,the highest cadmium accumulation was found in midgut in all three cadmium treatments,but at the adult stage,the highest cadmium content was found in fat body.In addition,the cadmium content in ovaries was much higher than in testes.When F1S.exigua was stressed by cadmium and the F_(2)generation was not fed a cadmium-containing diet,the larval survival,pupation rate,emergence rate and fecundity of the F_(2)generation were significantly reduced in the 51.2 mg kg^(-1)treatment compared to the corresponding F1generation.Even in the F_(2)generation of the 3.2 mg kg^(-1)treatment,the fecundity was significantly lower than in the parental generation.The fecundity of the only-female stressed treatment was significantly lower than that of the only-male stressed treatment at the 3.2 and 51.2 mg kg^(-1)cadmium exposure levels.When only mothers were stressed at the larval stage,the fecundity of the F_(2)generation was significantly lower than that of the F1generation in the 51.2 mg kg^(-1)treatment,and it was also significantly lower than in the 3.2 and 0.2 mg kg^(-1)treatments.The results of our study can provide useful information for forecasting the population increase trends under different heavy metal stress conditions and for the reliable environmental risk assessment of heavy metal pollution.
